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LESSONS 


IN 


Anatomy, Physiology, and Hygiene 



By C. L. HOTZE 


Author of 

“ First Lessons in Physiology “ Questions and Problems in Physics 
“ First Lessons iy Physics,” etc. 


REVISED AND ENLARGED 


BY 

E. D. LUCKEY, 

Prin . Elleardville School, St. Louis, 
AND 

A. R. MORGAN, 

Instructor in High School, St. Louis. 



a \ 



y\S'' 


ST. LOUIS: 

BECKTOLD PRINTING AND BOOK MFG. CO. 








Entered according to Act of Congress, in the year 1897, by 
W. B. BECKTOLD, 

In the Office of the Librariai} of Congress, at Washington, D. C. 


/ 


• i 



REFACE. 


Educators, and the people generally^ are agreed 
that a knowledge of “ the machine which we run and 
which runs us ” is of the utmost importance. The 
force and prominence of this fact have brought about 
the publication of this volume, which is a carefully 
revised and greatly enlarged edition of Hotze’s First 
Eessons in Physiology. 

In the preparation of this book the authors have 
kept in view the purposes, needs, and methods of the 
class-room, guided by their long experience in public 
school instruction and management. All the best ma¬ 
terial at command has been carefully examined and 
freely drawn upon ; one of the objects being to have 
this work fully abreast of the present knowledge on 
the subjects discussed, as far as its purposes will 
allow. A simple and clear style of expression has 
been used so that an intelligent understanding of the 
human body and its workings may be obtained by the 
average pupil in our elementary schools. 

The subject-matter has been arranged under several 
chief divisions rather than the old plan of lessons. 
These divisions being in general the great systems of 
the human body will, it is hoped, aid the student in a 
better comprehension of the subject. In the descrip¬ 
tion of each organ the endeavor has been: first, to 

(iii) 


iv ANATOMY, PHYSIOLOGY, AND HYGIENE. 

present a clear statement as to structure ; second, to 
set forth the functions ; and third, the care which the 
part should receive. In this connection the authors 
have discussed many disorders and given numerous 
hints as to treatment. Much care has been exercised 
in the making and the arrangement of cuts so as to best 
serYe the end in view — that of a correct knowledge of 
structure. To this same purpose topics, subtopics, 
and subjects of paragraphs have been indicated by dif¬ 
ferent kinds of type and numberings. In short, all 
that is possible in arrangement has been done to aid 
the student. 

A separate chapter has been devoted to the subjects 
of alcohol and narcotics. The views presented are 
intended to be such as are generally accepted by 
medical men to be in keeping with the best scientific 
thought. By being consistent with experience in the 
world it is thought that the pupil’s impressions will 
remain permanent. 

In conclusion it should be mentioned that the 
great works of Gray, Flint, Dalton, and Huxley have 
been considered undisputed authority and have been 
taken as standards. Also the writings of Hitchcock, 
Cutter, Carpenter, Hutchison, Lankester, Mace, 
Holmes, Hutchinson, and others have been con¬ 
sulted. 


PUBLISHER’S NOTICE. 

This Revised and Enlarged edition is intended to meet the 
demands of the schools to-day. The First Lessons on Physiology 
will still be published f*or classes already using it and for more 
elementary work. 



ONTENTS. 


DIVISION. PAGE. 

I. Introduction.1-14 

II. The Osseous System.15-46 

1. Bones .. 17 

2. The Skeleton.20 

Head.23 

Trunk ..28 

Limbs.33 

3. Functions ol the Osseous System.41 

III. The Muscular System .47-78 

1. Muscles and Fat .51 

2. Uses and Functions of the Muscles.68 

IV. The Skin, Hair, aud Nails .79-98 

1. Introduction.81 

2. The Skin.J ..81 

3. The Hair and Nails.85 

Functions and Hygiene of the Skin, Hair and Nails 87 

(V) 

















Vi ANATOMY^ PHYSIOLOGY, AND HYGIENE. 

DIVI8ION. . PAGE. 

V. The Circulation.99-142 

1. The Blood.103 

2. The Organs of Circulation.108 

Heart.*. . . 110 

Arteries.. t .... 112 

Veins. .116 

Capillaries.118 

3. The Circulation of the Blood.119 

4. The Lymphatic Circulation , . . . . . . 127 

5. Hygiene of the Circulation.130 

VI. The Respiratory System and Voice.148-184 

1. Introduction.145 

2. The Organs of Respiration.150 

Lungs.151 

Trachea.154 

3. Functions of the Organs of Respiration . . .160 

4. The Air. 166 

5. Hygiene of the Respiratory System.175 

VII. The Digestive System. 185-250 

1. Introduction.189 

2. The Organs of Digestion.191 






















CONTENTS. 


vii 

DIVISION. PAGE. 

YII. The Digestive System — Continued. 

3. Structure of the Organs of Digestion .... 191 

The Salivary Glands.193 

The Stomach.194 

The Intestines.195 

The Liver .199 

The Pancreas. 200 

The Lacteals .. . 202 

4. The Process of Digestion.205 

5. Food.223 

4>. Hygiene and Disorders of Digestive System . .241 

VIII. The Nervous System. 251-328 

1. Introduction.253 

2. The Cerebro-Spinal System.259 

The Brain .259 

The Spinal Cord.263 

The Nerves ..263 

3. The Sympathetic System .266 

4. Functions of the Nervous System.269 

5. The Organs of Sense. 282 

Touch. ; .284 

Taste.287 

Smell.290 

Sight.294 

Hearing.308 

6. Hygiene of the Organs of Sense *.312 

7. The Mind.32Q 


























Vlii ANATOMY, PHYSIOLOGY, AND HYGiENE. 

DIVISION. PAGE. 

IX. Alcohol ami Narcotics .829-356 

1. Alcohol.331 

2. Wine, Rum, Brandy, etc.345 

3. Tobacco .^ ... 347 

4. Narcotics. 349 

X. Emergencies... 357-364 

1. Drowning.359 

2. Cuts.361 

3. Burns.362 

4. Convulsions.. . 363 

XI. Appendix . .... 365-377 

1. Skeleton. 36 £ 

2. Circulation. 367 

3. Dissection.368 

4. Poisoning. 369 

5. Glossary 


371 


















I, 


INTRODUCTION. 


What a piece of work is man ! How nobis in rsason I 
how infinite in faculty! in form and moving how sxprsss 
and admirable! in action how like an angsl! in apprehen¬ 
sion how like a god! the beauty of the world! the -paragon 
of animals .— Hamlet, 


i 





/? NATOMY, 

^HYSIOLOGY, 

and PyGIENE. 



I. Introduction — General Science. 

All matter may be divided into two classes: 
Organic and Inorganic, which may also be termed, 
living and lifeless . Living objects are plants and 
animals;—lifeless, such substances as mineral-coal, 
iron, sand, rocks, water or air. Although in the 
present advanced state of science it is often difficult 

( 3 ) 


4 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


to draw the line of difference between living and 
lifeless things, yet that distinction is still main¬ 
tained, because between things having no life and 
substances such as wood or flesh, the differences 
are very striking. 

Organic matter includes the animal and the vege¬ 
table worlds — living things, while inorganic matter 
comprises the mineral world — lifeless substances . 

Organic (from ergon, 
work), having organs, or 
working parts. 

Inorganic, not having 
organs ; that is, having no 
working parts. 

The plant is the con¬ 
necting link between the 
mineral and animal kingdoms. 

Animals have life and nerve energy. Plants have 
life without the nerve energy. Minerals lack both 
life and nerve energy. 

The plant germinates, the animal breathes , while 
the stone does neither . In plants and animals 
there is change of parts, but in minerals there is 
no change. This germinating, breathing, and chang¬ 
ing process is dependent upon life. The principle, 
termed life, is always present in organic but never 



INTRODUCTION — GENERAL SCIENCE. 


5 


in inorganic matter. In fact, this is one of the 
most marked differences between the two kinds of 
matter.* In other words, an organism is derived 
from a parent; inorganic matter is not. 

Change is the great law of life. 

Organisms live, develop, and die; inorganic bodies 
are said not to live, develop, or die. 

The further distinction between these two great 
classes of materials is based upon form, coher¬ 
ence, growth, and composition. 

Form.—The sharp angles and straight lines of a 
crystal, the ,nearly regular features of most frag¬ 
ments of rock, are characteristic. On the other 
hand, notice the general absence of straight outlines 
in living structures, the curved shape of leaves and 
flowers, the rounded forms of the higher animals, 
and particularly those of the human body. Dis¬ 
tinguish between the fracture of a lump of mineral- 
coal and that of charcoal. It will be your impres¬ 
sion that inorganic matter, generally speaking, 
assumes forms of a severer pattern. 


* Matter is anything that occupies space. A distinct por¬ 
tion of matter is called a body. Matter may exist in three 
states; as, solid, liquid, and gaseous, respectively represented 
by ice, water , and vapor. 

Science is classified knowledge. 



6 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


Coherence. — Particles of sandstone cling together 
owing to cohesion, without having any other mutual 
relation. A fragment of sandstone truly represents 
the original rock of which it once formed a part, 
inasmuch as it possesses all the properties of the 
rock. The particles of a tree cohere likewise, but 
they are closely dependent upon one another. A 
piece of wood does not strictly represent the tree 
from which it came, because in different parts of 
the same tree the wood may have different prop¬ 
erties. Hence, the coherence of organized matter 
greatly differs from that of substances of the inor¬ 
ganic world. 

Growth.— If the growth of a crystal, or of an 
ordinary rock, could be plainly observed, it would 
be found to consist in a mere adding of particle 
after particle on the outside, without any interior 
development. Nor would it be found accompanied 
by decay, or repair, going on at the same time; 
whereas, plants and animals, during their growth, 
always decay in part — that is, while they are 
building up, they also lose waste matter, only the 
building up is far greater in quantity than the 
waste. This is true, regardless of the manner in 
which the plant grows, whether, for example, like 
most of our trees, it grows by adding superficial 


INTRODUCTION-GENERAL SCIENCE. 


7 


layers or rings around the stem, or, like Indian 
corn, by developing from within. Animals grow 
by interior development. Carbonic acid gas and 
water-vapor are two products of animal waste. 
Plants and animals make up the organic world, or 
world of organisms, and all organisms differ in 
their manner of growth from objects belonging to 
the inorganic world. 

Inorganic substances present a mere building up 
without corresponding development of all parts; 
while an organism develops throughout, and there¬ 
by attains gradually to a higher organization. The 
grain of corn generates the plant; the egg brings 
forth the bird; the infant develops into the full- 
grown man. Nothing of the kind takes place in 
inorganic matter. 

Composition.—Copper, gold and iron are ex¬ 
amples of elemental bodies; on being subdivided 
repeatedly, each yields its like again. Water is an 
example of a compound body; it is composed of, 
and may be resolved into, two elements,* hydro- 


* About sixty-five kinds of simple substances, termed ele¬ 
ments, either singly, or with two or more united, make up 
every material known. An element is a simple substance; that 
is, composed of only one kind of matter, as, oxygen , while a 
compound is made up of two or more elements, as sodium 



8 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

gen and oxygen. Clay, another compound body, 
consists of three or four elements. All these sub¬ 
stances are inorganic; and nearly all inorganic sub¬ 
stances are less complex in composition than 
organic bodies, such as wood or flesh. They are 
also more stable; that is, they do not decompose 
so readily. 

The Structure of a Higher Animal, required for 
the complete display of its capacities, may be repre¬ 
sented thus: — 

1. An apparatus to convert food into a fluid which 
will develop and maintain the body, and to remove 
waste materials. 

2. A system of vessels to convey this fluid to all 
parts of the body. 

3. A muscle or heart, which, by contracting and 
relaxing, pumps the fluid into the vessels. 

4. A mechanism for respiration, so as to purify 
the fluid by a fresh supply of oxygen. 

5. Contractile cords or muscles to set the different 
parts of the body in motion. 

6. A mass of nervous matter, with nerve fibres 
spreading over the body, to receive impressions from 


chloride — common salt. Salt contains sodium and chlorine , two 
elements, chemically united. 



INTRODUCTION-GENERAL SCIENCE, 9 

the outer world, and to convey manifestations of 
will, etc., to the various portions of the body. 

The discussion of plant and animal life is em¬ 
braced in many sciences. Biology, in a broad sense, 
means a discourse or treatise upon life , which may 
be either animal or vegetable, expressed in Zoology 
and Botany. In a narrower sense, it is applied to 
the study of animals. One of the divisions of 
Biology is Physiology . Physiology is the science 
which describes the action, functions and uses of 
animal organs. 

When the study relates to man, it is styled 
Human Physiology , but when referring to the lower 
animals, it is termed Comparative Physiology . 

Divisions of the Subject. — Physiology proper 
naturally divides itself into three departments: 
Anatomy , Physiology , and Hygiene . Anatomy 
treats of the structure of the body and its individ¬ 
ual parts. 

Physiology ,* in a restricted sense, treats of the 
functions of the body and its organs. 

Hygiene treats of the laws of health. 


* It will be noticed that the term Physiology is used in two 


senses. 



10 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


The value of a thorough knowledge of physi¬ 
ology, in all its departments, can scarcely be esti¬ 
mated. If one be well, a knowledge of physiology 
will keep him so. While on the other hand, if 
one be sick, the same knowledge will enable him 
to regain that priceless treasure — good health. A 
fitting paraphrase of the well-known proverb would 
be “ Good health is to be chosen rather than great 
riches.” How many thousands are the victims of 
disease and premature death on account of igno¬ 
rance of the laws of their being. What pleasures 
are added to the joys of existence by “ eating to 
live” rather than “living to eat!” Mens sana in 
corjpore sano is a maxim whose truth is clear. The 
ancients were not so far advanced in the sciences 
as the moderns are, yet we are indebted to them 
for many valuable truths. Chilo, one of the great¬ 
est of the ancient philosophers, expressed this wise 
saying: “Know thyself.” Then, let him who 
would fulfill the laws of life know himself. 


INTRODUCTION — GENERAL SCIENCE. 


11 


REVIEW QUESTIONS. 

1. What is science? Give the states of matter. 

2. Define matter, and name its classes. 

3. Why is it difficult to draw a distinction between the two 
great classes of matter? 

4. Give the divisions of organic matter. 

5. What is the derivation of the word organic? 

6. In what way is the plant the connecting link between the 
mineral and the animal kingdoms? 

7. Name the three kingdoms of nature and state how they differ 
from one another. 

8. How are these kingdoms closely related? 

9. What is the great law of life? What is life? 

10. Explain the difference in derivation between organic and 
inorganic matter. 

11. What can organisms do? 

12. Give the leading distinction between these two great classes 
of matter. 

13. Form: What is characteristic of crystals? Of living struc¬ 
tures? What is meant by “inorganic matter, generally speaking, 
assumes forms of severer pattern? ” What have you noticed in 
snow crystals as to beauty and regularity of form? 

14. Coherence: How does the coherence of organic and inor¬ 
ganic matter differ? What holds the living body together? 

15. Growth: Explain the difference in the growth of crystals 
and organic bodies. What opposite processes are going on in 
plant and animal bodies at the same time? In what two ways do 
plants grow? Give examples of two kinds of plants differing in 
manner of growth. How does the growth of animals differ from 
that of plants? 


12 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

16. Composition: What is an element? How many elements 
are there? By what science are elements united to form com¬ 
pounds? Define compound. Name a compound, giving the ele¬ 
ments composing it. Which are more complex in composition, 
organic or inorganic “ bodies? ” Which are more stable? 

17. What are required for the structure of a higher animal? 

18. In what way is the discussion of plant and animal life a 
broad one? 

19. What are some branches of Biology? What one relates 
to the lower animals? 

20. Define Physiology, and give its two phases. 

21. Give the divisions of Physiology, defining each. 

22. Por what reasons ought one to study the subject of Phys¬ 
iology? What is the way of the world regarding “ good health? ” 
Whom should we blame for our ill-health? Explain the mean¬ 
ing of the phrases: “ Eating to live,” and “Living to eat. ” Are 
there some notable exceptions to the sentiment, contained in mens 
sana in corpore sano ? Give an instance, or two, to show that 
the ancients were very wise. To what country did Chilo belong? 
What can you tell about him? What does “Know thyself” 
mean? Give an instance where a knowledge of physiology was 
very beneficial. 


INTRODUCTION-GENERAL SCIENCE. 


13 


BLACKBOARD OUTLINE. 

{ Animal Kingdom. 
, Vegetable “ 

[2. Inorganic (lifeless) Mineral “ 


Distinctions between 
Organic and Inor¬ 
ganic Matter. 


1. Form. 

2. Coherence. 

■{ 3. Growth. 

4. Composition. 

5. Derivation.* 


{ 1. Botany. 

( Human Physiology. 

2. Zoology-^ 

l Comparative Physiology, 


f 1. Anatomy. 

I 

Physiology. { 2. Physiology. 

I 

(3. Hygiene. 


* That is, organic matter is derived from a parent, while inorganic is not. 



















II. 


THE OSSEOUS SYSTEM. 


Man is all symmetrie 
Full of proportions, due limbs to anothEr, 
And all to all the world besides, 

Each part may call ths farthest, brother, 
For head with foot hath private amitie, 
And both with moons and tides, — Herbert, 






















t 









II. The Osseous System. 


1. BONES. 

Experiment.—Place the thigh-bone or “ drum¬ 
stick’ ’ of a chicken on a shovel and put the shovel in 
the fire. Leave it there a few minutes. Take it out 
of the fire and examine. You will observe that the 
shape of the bone is unchanged, but that it is no 
longer strong and tough; that it will not support as 
much weight as before. This is the condition of the 
bone when it has lost its animal matter.* 

Experiment. — Place another bone of the same 
kind in a glass or bottle filled with common vinegar, 
or diluted muriatic acid mixed in the ratio of a 
wine-glass of acid to a pint of water. Leave the 
bone there two or three days. Now remove the 
bone and wash it in clear water. You will ob¬ 
serve that the shape is unchanged, but that its 


* Bones thus burned furnish the phosphorus of the chemist. 
If the animal matter is only charred the “ bone-black ” of com¬ 
merce is made. 


2 


( 17 ) 



18 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

firmness is destroyed; that it may now be bent 
without breaking — indeed, if the experiment is 
carefully performed it may 
be tied into a knot, as seen 
in the accompanying cut. 
This is the condition of the 
bone when it has lost its 
mineral matter. 

The Composition of bones 
is now seen to be a close 
union of animal and mineral 

substances. In the normal 

\ 

bone both substances exist 
pig. l. in definite proportions. In 

youth these are nearly half and half. A defi¬ 
ciency in the mineral ingredients (chiefly lime), 
as is the case with bones in early life, causes 
them to bend readily; while an excess of lime, 
always found in the bones of old people, renders 
the bones brittle. 

The entire bone is at first composed of cartilage, 
which gradually ossifies or turns to true bone.* 
Certain portions near the joints are long delayed in 

* The ossification of the bones on the sides of the head, for 
example, begins by a rounded spot in the middle of each one. 
From this spot the ossification extends in every direction. 




THE OSSEOUS SYSTEM. 


19 


this process, and by their elasticity assist in breaking 
the shock of a fall. 

The Structure of bones shows a network of small 
canals and layers of bone substance. Bones are less 
dense at their centers; many of them contain a fatty 
substance called the marrow. Bones grow and con¬ 
stantly renew their particles. 



FIG. 2. 


A thin slice of Bone, highly magnified, showing the lacunae, 
the tiny tubes (canaliculi) radiating from them, and four 
Haversian canals, three seen crosswise and one lengthwise. 

The Growth of Bones. — Every bone of an adult 
was at one time a cartilage, as we have said above. 
It did not become hardened uniformly throughout its 
mass, but the process of ossification — that is, the 
deposition of mineral matter in the cartilage—took 


20 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


place first at particular points, called the centers of 
ossification . Thus the long bones of an infant con¬ 
tain at least three such centers or bony masses, one 
in the middle part of the bone (then as yet a carti¬ 
lage), and one situated toward each end. In the adult 
these three osseous centers are united into one solid 
bone. 

When the edges or ends of bones in their growth 
come to touch each other, they either form joints or 
articulations, in order to enjoy motion upon each 
other; or they grow firmly together, forming sutures. 
Sutures may be readily ascertained in the bones com¬ 
posing the skull. 


2. THE SKELETON. 

The Skeleton, or framework of the “ house we 
live in,” consists of all the bones in the human body, 
the total number of which is about two hundred and 
six, excluding the teeth. Besides, there is found a 
firm, elastic tissue called cartilage or gristle, such as 
the outer ear or the lower part of the nose. These 
cartilages are found mainly at the joints between the 
bones as cushions. 

The skeleton is usually divided into three distinct 
portions: the head , the trunk , and the (upper and 
lower) limbs (Fig. 3). It contains three cavities; 


THE OSSEOUS SYSTEM. 


21 


the uppermost is a hollow box of bone, the skull , or 
cranium; this contains the brain, and has attached 
to it the jaws and the remaining bones of the 
head. 

Below this a bony case or basket is seen, called the 
chest or thorax; and further down a bony basin, 
th q pelvis. The chest and the pelvis, together with 
the backbone, form the trunk of the body. The 
arms, or upper extremities, are attached to the 
upper part of the chest by means of the collar¬ 
bone and the shoulder-blade . The legs, or lower 
extremities, are fastened to the lower part of the 
trunk. 

Bones, like all organic structures, consist of cells , 
that is, of cellular tissue; the cells are more or less 
of a hexagonal form. Bones are renewed even more 
rapidly than any other portion of the body except the 
nails, the skin and the hair. The natural process by 
which broken bones are restored is remarkable. The 
immediate result of the injury is an effusion of blood 
around the broken parts. This is soon replaced by a 
watery fluid, which, after some time, thickens into a 
jelly-like mass. In a month or two this mass hard¬ 
ens, and slowly acquires the properties of bone; 
months after this the bones, if carefully treated, 
unite perfectly. 


22 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 



FIG. 3. 


Toes. 


















THE OSSEOUS SYSTEM. 


23 


The Head (Fig. 4) consists of the bones of the 
skull, face and ear. Its principal parts are: — 

1. The frontal bone. 

2. Two side bones , which form the uppermost part, 
and part of the right and left sides of the skull. 



fig. 4. 


3. Two temporal bones , one on each side of the 
lower part of the frontal bone. 

4. The occipital bone , extending down the neck. 

5. The upper jaw . 6. Two cheek bones. 7. Nose 

bone. 


u 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


8. The lower jaw, easily separable from the remain¬ 
ing parts of the head. 

9. The sphenoid bone , forming the base of the skull 
(not visible in Fig. 4). 

The upper jaw contains the upper row of teeth, the 
lower jaw, the lower. The lower portion of the nose 
consists of cartilage, which remains soft during life. 
The roof of the mouth is a thin but hard bone, 
forming part of the upper jaw. 

The various bones of the head are firmly 
joined together, although they contain fissures and 
holes. 

According to the preceding, the skeleton is com¬ 
posed of head, trunk and limbs; and the trunk 
separable into chest or thorax, and pelvis. The 
young student will do well to observe that the head 
contains two distinct cavities ; the cavity of the skull 
and that of the face, which are entirely separated 
from each other. The former contains a mass of 
nervous substance, which is called the brain. This 
substance is continued down to the lower end of the 
pelvis in the shape of a downward tapering cord, 
called the spinal cord. This cord together with the 
brain pass under the name of cerebrospinal axis. 
Thus, we discover that the skull together with the 
vertebral column (Fig. 5) form a tube very much 


THE OSSEOUS SYSTEM. 


25 


cs 


VC 


AL_ 


expanded above and exceedingly narrow at its 
lower end; and that this tube is completely insulated, 
in the first place, by the fig. 5. 

bones of the skull, and 
secondly, by the vertebral 
bones or vertebrae . 

The other cavity, that of 
the face, contains the 
mouth. The mouth is part 
of another tube, called the 
alimentary canal , which 
extends from the mouth 
through the entire length 
of the trunk in front of 
the vertebral column (Fig. 

5). The cavity of the 
mouth may be considered 
the expanded upper end of 
the alimentary canal, just 
as the cavity of the skull 
forms the upper expanded 
end of the tube containing 
the spinal cord. 

The cavity of the mouth contains two rows of 
teeth, one in the upper jaw, the other in the lower. 
Each tooth has crown , nech and fang or fangs. The 
crown is the portion which projects beyond the gum. 



VERTICAL SECTION OF THE 
HUMAN BODY. 

A. L. —Alimentary canal. 
V. C. — Vertical column. 

C. S. — Cerebro-spinal axis. 








26 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

The neck is that portion immediately below the 
crown and on a level with the edges of the gum. 
The fang, or fangs if there be more than one, com¬ 
prises all below the neck (Fig. 6). 

The crown is covered with an exceedingly hard 
substance, called enamel; this is the hardest portion 
of a tooth, and the hardest substance in the human 
body. It forms a very thin layer, and serves as a 
protection to the principal constituent of all teeth, 


a b c d e f 



fig. 6. 


the dentine or ivory. This dentine is hollowed out 
into a cavity, which contains a very sensitive mass 
of nervous matter, the tooth pulp (Fig. 6, a ). 
Teeth are partially composed of bony matter; they 
differ from bones in possessing enamel and dentine, 
which bones have not. Teeth have no growth. 

There are thirty-two teeth in number, sixteen in 
each jaw. The four front teeth in each jaw are 






THE OSSEOUS SYSTEM. 


27 


adapted for cutting purposes, and therefore named 
incisors (b). On each side of them is a tooth with 
one cusp —that is, with a pointed crown (c). It is 
called the eye-tooth , or, because it resembles the long, 
tearing tusk of the dog, the canine . Next on either 
side is a tooth (d) with two cusps on the crown, 
larger than the preceding teeth, and called bicuspid. 
Adjacent to it are teeth with more than two cusps, 
the molars or grinders (e and f), the broadest and 
most powerful of all. The crowns of the molars in 
the lower jaw have four or five cusps, while those in 
the upper have one cusp less. 

In the early period of life, each jaw has ten tempo¬ 
rary or milk teeth. At the age of six or eight the 
upper portions of these teeth fall out or are “ shed,” 
while the fangs are absorbed. Then appears 
the second or permanent set of teeth, thirty-two in 
number. The following formula shows that the 
molars of the child are replaced by the bicuspids of 
the adult: — 


Formula of Arrangement and Number of Teeth. 

Mo Ca In Ca Mo 
Upper, 2 1 4 1 2 = 10 

Temporary _ _ 

Teeth. 

Lower, 2 1 4 1 2 = 10 





28 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


Mo Bi Ca In Ca Bi Mo 
Upper, 32 14123 = 16 

Permanent __ 

Teeth. 

Lower, 32 1 41 2 3 = 16 

Important Facts. — Sudden changes of tempera¬ 
ture, owing to very cold or very hot food or drink, 
are dangerous to the teeth, as they may cause the 
enamel to crack. Acids and metal toothpicks should 
be avoided. Teeth require frequent cleansing with 
water and a soft brush, especially after meals. Any 
injury to the enamel is irreparable, and, as it causes 
the dentine beneath to decay, may involve the loss of 
the tooth. 

Therefore cracking hard nuts with the teeth, biting 
thread, etc., should be avoided. Furthermore, the 
teeth should be examined at least once a year by a 
dentist, so that if any small cavity should be found it 
may be filled and further decay prevented. At such 
an examination the tartar, a deposit at the edges of 
the gums, which is very injurious, should be carefully 
removed. 

The Trunk constitutes the second chief division of 
the skeleton.* This is a very important part of the 

* The carcass of a quadruped, if placed in a wooden box punc¬ 
tured on all sides, and buried in the ground, close by an ant-hill, 
will after a few weeks be reduced to a skeleton, which may be 
used to advantage in studying the human skeleton. 






THE OSSEOUS SYSTEM. 


29 


framework of the human body. It is complex in 
structure and has the great cavities which contain the 
vital organs of the man. There are two of these 
cavities. The upper one, or chest , contains the heart 
and lungs; the lower one, or abdomen , holds the 
stomach, liver, kidneys, and other organs. The bones 
of the trunk may be divided into those of the spine , 
the ribs , and the hips. 

The Spine is the upright column (Fig. 5) called 
the back-bone , by which the head is supported. It 
consists of twenty-four separate vertebrae, which 
are so fastened together that the entire number 
appears as an unbroken pillar, forming the central, 
most important, and, let us add, the most wonder¬ 
ful part of the skeleton. Nearly all the organs of 
the body seem to rely upon it for their support. 
It helps to form the back wall of the chest and 
abdomen, which are maintained by the pelvis, or 
haunch bone . The spine rests upon the pelvis like 
a column upon its base. 

The Vertebrae and joints of the back-bone may be 
ascertained by the touch; they begin with the back 
part of the neck and pass down to the pelvis. In a 
similar manner locate the ribs, which extend from the 
right and left of each vertebra in the thorax and en- 


30 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


circle the chest. They are fastened in front to the 
breast-bone, or sternum . Find the two collar-bones, 
or clavicles , and observe their form. Next examine 
the two shoulder-blades; together with the clavicles 
they form the shoulder, and protect the lungs from 
above. 

The vertebrae are perforated, that is they contain a 


FIG. 7. 



Two Vertebrae. 
Side View. 


A Vertebra. 
Horizontal Section. 


nearly oval cavity about an inch wide, filled with the 
spinal cord (Fig. 7, d). This cord extends down to 
the lower end of the pelvis. The spinal column pro¬ 
tects the spinal cord within; it serves to bear the 
head aloft and to give the body its erect position. 
Between the vertebrae are the usual cartilaginous 


THE OSSEOUS SYSTEM. 


31 


cushions. These are thick and 
strong and together with the double 
curve of the spine prevent any jar 
from reaching the brain when we 
jump, run or fall. Here we may 
observe the great precaution which 
is taken to guard the precious 
organs. 

Each vertebra presents the appear¬ 
ance of a hollow cylinder, to the 
rear portion of which are attached 
seven superficial elongations, or pro¬ 
cesses (Fig. 7, b and c). To these 
processes are joined ribs, ligaments, 
and muscles. 

The Ribs, twenty-four in number, 
are in pairs in the two walls of the 
chest. The number of ribs fast¬ 
ened to the sternum is fourteen, 
seven on each side. The eighth 
and ninth ribs, on each side, do not 
reach far enough to the front; the 
tenth, eleventh, and twelfth are 
shorter yet. These ten ribs are 
called the “ false 99 ribs. 



neck, cervical; 
the twelve of the 
back, dorsal; the 
five of the loins, 
lumbar; a, the sac¬ 
rum, and 5, the 
coccyx, comprising 
the nine “false 
vertebrae.” 


32 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 




The form of the chest when in its natural condi¬ 
tion is that of a cone with 
the small end upward. Being 
long and slender the ribs give 
lightness; and curved in di¬ 
rection, give strength; with 
cartilaginous connection in 
front they give elasticity,— 
all of which are necessary 
for the protection of the 
FIG> 9 delicate organs within as well 

The Chest, or Thorax. as their action. 

a, the sternum; b to c, 
the true ribs; d to h, the 

false ribs; g, h , the float- The Pelvis supports the 

ing ribs; i, k, the dorsal spinal column and the abdo- 
vertebrae 

men. It is formed by the two 
hip-bones, which are held together by the lower part 

of the spinal column, the 
sacrum . 

During the day the spi¬ 
nal column, while in erect 
position, supports the 
weight of the head, arms, 
and nearly the entire 
FIG 10> trunk. This compresses 

The Pelvis, a, the sacrum; the layers of cartilage be- 

b, b, the right and the left tweea each ir of verte _ 

mnominatum. 1 


THE OSSEOUS SYSTEM. 


33 


bras so as to diminish the length of the column. 
Hence, the human body is actually a little 
shorter towards evening, and resumes its nor¬ 
mal length when lying in a horizontal position, 
or after a night’s rest. Elderly persons shrink 
in height, because their intervertebral cartilages 
harden and become thinner; this accounts for their 
stooping posture. Persons in the habit of bend¬ 
ing the head forward too far compress the front 
part of those cartilages, while the rear portion thick¬ 
ens. In course of time the cartilages lose their 
elasticity, and the spine becomes curved or 
“ crooked.” The erect position of the spinal 
column is one of the essential requirements of 
health. 

The Limbs. — Two sets of extremities branch from 
the trunk, viz.: the upper and the lower. They are 
very similar in structure. 

Examine your arms and locate their bones. You 
will find a long bone in the upper arm, and two 
long bones in the lower. So there is in the upper 
leg a long bone, the longest and strongest bone in 
the skeleton; and there are, also, two long bones 
in the lower leg. 

The Shoulder is made up of two bones, the collar- 


3 


34 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


bone (clavicle), and the shoulder-blade (scapula). 
The clavicle is a long slender bone almost the 
shape of the italic f, named from 
clavis , the Latin word for key, which 
the bone resembles in shape. This 
bone holds the shoulder-point or scap¬ 
ula back. The scapula is a thin, flat, 
triangular bone resting against the 
back of the chest and formed to make 
the foundation for the muscles of the 
shoulder. 


The Long Bone in the upper arm 
is called the humerus . 

The Bones of the Forearm are the 
radius , which is on the side with the 
first finger, and the idna. 


The Hand (Fig. 11) is composed 
of three parts: the fingers, the palm, 
and the wrist. The wrist contains 
eight little bones, placed in two 

Bones of the Arm 

and Hand. rows ; together with the bones of the 
forearm, they form the wrist-joint. 
The palm has five bones. The four fingers 
have three bones each; the thumb contains only 




THE OSSEOUS SYSTEM. 


35 


two. The entire hand, therefore, contains twenty- 
seven bones. 

The Foot, in a similar manner, is composed of the 
toes, the metatarsus, and the tarsus, or instep. The 
great toe contains two bones; the remaining toes, like 
the fingers of the hand, have three bones each (Fig. 
11). The instep has seven bones; the metatarsus, five. 
In all there are twenty-six bones in the foot. The 
heel supports the rear portion of the foot, or the 
whole body when the body is in erect position. 

The Knee-Pan covers the forepart of the knee-joint. 

The mechanism which adapts the limbs in the 
human body to their manifold uses, is remarkable for 
its effective plan and devices. No animal exhibits a 
system of joints which is movable in so many direc¬ 
tions, and yet is so firm and stout. No animal 
possesses such gracefulness in the motions of its 
limbs, combined with so vast a capacity of exertion 
and endurance. 

The limbs are joined to the trunk in a manner such 
that they enjoy motion in every direction — upward, 
downward, forward, backward, and in a circular 
manner. This is secured by a ball-and-socket joint 
where the globular-shaped head of a bone plays in a 


36 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


cup or socket. The elbow and the ankle have each a 
hinge-joint , which allows forward and backward 
motion only. 

The foot does not rest upon its whole lower surface, 
but, having the form of an arch, it touches the 
ground only at the heel and at the ball of the toes in 
front. All the bones composing the arch, or 4< hollow 
of the foot,” are fastened to each other by ligaments 
in such a manner as to give them a large amount of 
spring-force with which to resist the effects of pres¬ 
sure produced by the weight of the body and by the 
jar against the ground. To convince one of the truth 
of this, he needs but place the hollow of the foot 
upon the round of a iadder. 

Ligaments and Joints.— The movable joints are 
fastened together by ligaments,— firm fibrous bands 
with very little mobility. The bone to which a liga¬ 
ment is fastened may be broken by an accident, with¬ 
out harm to the ligament itself. The ligaments are 
tough and not easily hurt; but when we do “ sprain ” 
a joint, which means that we have torn or overstretched 
its ligaments, they recover slowly. If our joints were 
formed by the direct contact of bones, these bones 
could scarcely play upon each other; hence, there is 
cartilaginous tissue between them, to give them a 
greater or less amount of play and elasticity. In the 


THE OSSEOUS SYSTEM. 


37 


movable joints the surfaces which play upon each 
other are covered with cartilage. Moreover, they are 
enveloped by a sort of sac, which secretes a lubricat¬ 
ing fluid resembling the white of an egg, called 
synovia. 

The joints of the body seem to be movable; but 
many, like the joints of the head-bones, are fixed, in 
the manner of the joints of a chair or table. In the 
spine the joints have little motion, but are not freely 
movable like the joints of the limbs. The joints may, 
then, be classed as,— 

Immovable. 

Slightly movable. 

Freely movable. 

The Movable Joints are of several kinds. Chief 
among these may be mentioned, the hinge joint, rep¬ 
resented by the elbow and ankle; the ball and socket 
joint, of which the articulation of the femur and 
pelvis is an example. 

Important Facts. — Animals can not move their 
claws separately; man is able to move any of his 
fingers independently. No animal except the bat is 
competent, with its fingers, to make a span equal to 
the entire length of the hand. While many an 
animal has something like fingers, while the bird 


38 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


possesses a flying apparatus, and the horse greater 
capacity for running than man, man alone has so 
perfect a machine as the human hand with which to 
execute such complicated motions and to assume such 
manifold positions and forms. 

Cartilage. —Examine, and compare with each 
other, the nasal cartilage, the external ear, and the 
gullet of a bird. The first is an appendage to a 
bone, the second is not directly connected with any 
bone, the third is a structure entirely independent of 
bones. All three are illustrations of a dense, firm 
substance, called cartilage, or gristle. It is nearly 
related to bone, but lacks the mineral ingredients of 
bone, and is, therefore, softer and more elastic. 

The Chief Uses of Cartilage are the following: — 

(1.) To yield smooth surfaces for easy friction in 
the joints; and to act as a cushion in shocks. 

(2.) To fasten bones together without destroying 
freedom of movement, as between the vertebrae. 

(3.) To serve as a firm yet not unyielding frame¬ 
work, as in the larynx and trachea. 

(4.) To adapt itself to all purposes where firmness, 
toughness, elasticity, and strength are required. 


THE OSSEOUS SYSTEM. 


39 


The Larynx and Trachea.— To the rear of the 
tongue is an aperture, the glottis , with a sort of 



Trachea. 


Epiglottis. 


Larynx. 


Right Bronchus. 


Left Bronchus. 


Fig. 12—Larynx and Trachea. 


















40 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


fleshy cover, the epiglottis (Fig. 12). This aperture 
leads to a cavity, the larynx, whose sides are com¬ 
posed of cartilage. 

The lower continuation of the larynx forms a long 
tube, the trachea , or windpipe, composed of cartilag¬ 
inous rings, some of which may be felt from with¬ 
out. These rings are complete only in front; in the 
rear where the trachea rests against the gullet, their 
ends are connected with each other by a thin mem¬ 
brane and by muscular fibres. 

The trachea, after entering the thorax, separates 
into two branches, the right and left bronchi . These 
enter the lungs and divide further into a great many 
smaller bronchial tubes. 

The larynx is the organ of the voice. It contains 
within its cartilages, immediately below the epiglottis, 
two elastic lips, known as the vocal cords. These 
cords are controlled by certain muscles, so they can 
close the larynx against the passage of air to or from 
the lungs. They can also be relaxed, or shortened 
and lengthened, so as to throw currents of air passing 
between them into vibrations — that is, so as to pro¬ 
duce sound. During inspiration the vocal cords are 
widely separated; during expiration they relax some¬ 
what, and are nearer together. 


THE OSSEOUS SYSTEM. 


41 


3. FUNCTIONS OF THE OSSEOUS SYSTEM. 

The Functions of the bones in the human body are 
comprehended by the terms protection , support , and 
motion. 

The bones of the skull form a box, the walls of 
which are an excellent protection for the delicate 
organ contained, the brain. 

The frontal bone projects over the eye, forming a 
shield for the eye-ball. 

The ribs and the spine constitute the conical box in 
which the vital organs, the lungs and the heart, are 
encased, very carefully guarded from harm. 

The great column, the spine, so wonderfully con¬ 
structed, is the chief support for the entire body. 
Bones of the lower limbs likewise are for sup¬ 
port as well as for locomotion. The foot with 
its graceful arch and all its bones so carefully 
adjusted is admirably constructed for sustaining the 
weight of the body to the best possible advantage. 
And few persons even consider how important this 
part of the skeleton is. Consequently it is gen¬ 
erally mistreated. Ill-stmped shoes fashioned ac¬ 
cording to some abnormal imagination rather than 
in keeping with nature’s model are universally 


42 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


sought, thus abusing that which was constructed 
for satisfaction and use. 

The great variety — almost endless variety — of 
motions of which the body is capable is directly 
due to the great number and varied shapes of 
bones in the skeleton. Study for a moment the 
motions of the arm and hand. How numerous and 
how varied in direction and position! This could 
not be were it not for the great number of bones 
in these members of the body. True, not to the 
bones alone is all this due, but in conjunction with 
ligaments and muscles. 

From these statements of facts it may be seen 
that, in truth, the functions of the skeleton are 
protection, support, and motion. 

Important Facts. — The disease, rickets , frequent 
in early life, is due to want of mineral matter for 
the bones; on account of which they become soft 
and easily bent. Children subject to rickets should 
have plenty of fresh air, sunshine, nourishing food, 
comfortable clothing, and the best of hygienic care 
in general. There is danger of causing bow-legs by 
standing children on their feet too soon, curvature of 
the spine is apt to result from sitting too long at 
a desk or table in an abnormal position. Round 


THE OSSEOUS SYSTEM. 


43 


shoulders, small, weak lungs, and spinal diseases are 
frequent results of improper position of the spinal 
column. The ligaments, which bind the bones to¬ 
gether in a joint, may be strained, twisted, or torn 
from their attachments. A sprain is quite a serious 
thing and requires careful attention and this should 
not be delayed. 

“ Fractures are usually met with when the person 
is dressed. Therefore, unless there is bleeding, or 
something to call for immediate exposure and exam¬ 
ination of the damaged part, do not be in a hurry 
to remove the clothes. If the arm be hurt, extem¬ 
porize a sling from a neck-handkerchief or some 
other article of dress, and support the arm from 
elbow to wrist, tying the ends of the handkerchief in 
a knot over the coat-collar behind. If the thigh or 
leg be in pain, fasten the injured limb to its fellow 
by a cravat bandage or two, and take care that they 
lie side by side, and on the same level; or fasten 
outside the clothes some temporary support — a 
piece or two of straight stick, with a bandage — 
and then remove the sufferer quietly and carefully 
to some house near at hand. If medical aid be 
available, send for it without any delay; and be 
careful, if in the country, and at some distance 
from the doctor’s house, to forward a clear state¬ 
ment as to the apparent nature of the accident, which 


44 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


limb is hurt, and where and how it happened. Let 
this statement, too, be in writing, if possible. It 
may well happen, however, that skilled assistance 
cannot be had, and in this case the patient should 
be undressed quietly and cautiously. It will be far 
better to slit up the dress on the arm or leg with a 
pair of scissors than to pull it off; but however the 
covering of the injury may be managed, it must be 
done very slowly and gently, and the limb should 
be supported so as to prevent jarring and shaking 
to the damaged part. It must be carefully kept, 
too, in a right direction, for otherwise some sharp 
splinter of bone may penetrate the hitherto un¬ 
wounded skin.”— First Help in Accidents and 
iSickness . 


THE OSSEOUS SYSTEM 


45 


REVIEW QUESTIONS. 

1. What is the composition of bones? 

2. Contrast bones of a youth with those of an old person as to 
composition. 

3. How do bones ossify? 

4. What is the number of bones in the body? 

5. Name the principal parts of the head. 

6. What are the parts of a tooth? 

7. Classify the teeth. 

8. State some facts as to the care of the teeth. 

9. Describe the spine. 

10. Why is not the spinal column made up of a single bone in 
place of the vertebras? 

11. Why are not all the ribs attached to the sternum? 

12. When has the human body greater length than usual? 

13. State why this is the case. 

14. How does bone differ from cartilage? 

15. What are some of the uses of the pelvis? 

16. What bones constitute the shoulder? 

17. Name the bones of the arm. 

18. State some fact about animals in comparison with man. 

19. What are the chief uses of cartilage? 

20. Give the three great functions of the osseous system. 

21. State three facts as to the care of the bones. 


46 


ANATOMY, PHYSIOLOGY, AND HYGIENE 


BLACKBOARD OUTLINE. 

THE SKELETON. 

I. Tlie Head —28 Bones. 


1. The Skull - 

2. The Face — 

3. The Ear — 

8 Bones. 

14 Bones. 

6 Bones. 

1 Fron'tal (forehead) 

2 Na'sals (bridge of 

2 Mal'leus bones 

1 Occip'ital (back of 

nose). 

(“ mallet ”). 

head). 

2 Ma'lars (cheeks). 

2 Incus bones 

2 Pari'etals (side of 

2 Lach'rymals 

(“ anvil ”). 

head). 

(“ tear ”). 

2 Sta'pes bones 
(“ stirrup ”). 

2 Tem'porals (tem¬ 
ples). 

1 Sphe'noid(“wedge- 
shaped ”). 

1 Eth'moid (“ sieve¬ 
like ”). 

2 Pal'ates. 

2 Tur'binated bones. 

2 Upper max'illary 
bones (jaw). 

1 Lower max'illary 
bone. 

1 Vom'er (“ plough¬ 
share” between 
nostrils). 


II. TI*e Trunk— 54 E^ones. 


1. The Spine — 

26 Bones. 

• 7 Cer'vical ver'tebrae 
(neck). 

12 Dor'sal ver'tebrre 

5 Lumbar. 

1 Sac'rum (“ sacred ” 
— used in sacri¬ 
fices). 

1 Coc'cyx (“ cuc¬ 
koo ”). 

2. The Chest — 

26 Bones. 

14 True ribs —7 on 
each side. 

10 False ribs —5 on 
each side. 

1 Ster'num (breast 
bone). 

1 Hy'oid (base of 
tongue). 

3. The Pelvis — 

2 Bones. 

2 Innomina'ta Chip — 
the name of one is 
Innominatum). 

III. The Extremities 

— 124 Bones. 


i. Upper Extremities 

2. Lower Extremities 


64 Bones. 

60 Bones. 


1 Clav'icle ( clavis, 

1 Fe'mur (thigh). 

• 

key). 

1 Patel'la (knee-pan) 


1 Scap'ula (shoulder 

1 Tib'ia (leg — Latin 


blade). 

for “ flute ”). 


1 Hu'merus (arm). 

1 Fibula (leg —Latin 


1 Ul'na (forearm — 

for “ pin ”). 


Greek for elbow). 

7 Tar'sals (ankle). 


1 Ra'dius (forearm — 

5 Met'atar'sals (in- 


Latin for spoke). 

step). 


8 Car'pals (wrist). 

14 Phalanges (toes — 


5 Met'acar'pals 

2 in great toe 3 in 


(palm). 

14 Phalan'ges (fingers 
— 3 In each finger 

2 in thumb). 

i ach other one). 



















III. 

THE MUSCULAR SYSTEM. 

w 


Behold the outward moving frame, 

Its living marbles jointed strong 
With glistening band and silverg thong, 

And linked to reason's guiding reins 
Bg myriad rings in trembling chains, 

Each graven with the threaded Zone 

Which claims it as the master's own ,— Holmes. 














MUSCLES OF THE FRONT FIGURE. 


A , Platisma Myoides. Broad muscle of the neck, a , Sterno- 
Hyoideus. Muscle between the breast and tongue bones, b, 
Mastoideus. Mastoid muscle. B, Deltoides. The muscle cover¬ 
ing the shoulder-joint. C , Biceps Brachii. Two-headed muscle 
of the arm. D, Pronator Radii Teres. Pronating muscle of the 
arm. E , Supinator Radii Longus. Supinating muscle of the arm. 
F , Flexor Carpi Radialis. Radial flexor of the wrist. G, Palmaris 
Longus. Long bending muscle of the hand. H, Flexor Carpiul- 
naris. Ulnar flexor of the wrist. I, Pectoralis Major. Large 
muscle of the chest. K, Obliquus Descendens. Oblique descend¬ 
ing muscle. LL, Rectus. Straight inuscle. £,Linea Semilunaris. 
Semilunar line. M , Linea Alba. White line. N, Poupart’s liga¬ 
ment. Poupart’s ligament. OO s Sartorius. The “ tailor’s muscle.” 
P, Tensor Vaginae Femoris. Stretcher of the fascia lata. U, Psoas 
Magnus. Large lumbar muscle. F, Vastus Externus. Great external 
muscle. W, Rectus Femoris. Straight femoral muscle. X, Vastus 
Internus. Great internal muscle. Y, Gastrocnemius. Muscle 
of the calf of the leg. y f Soleus. A broad flat muscle of the 
leg. Z, Tibialis Anticus. Anterior muscle of the leg. 

( 49 ) 


4 





f 


















III. The Muscular System. 

1. MUSCLES AND FAT. 

Experiment. — Stretch out one arm and let its 
upper part be grasped by another person. Then 
slowly bend up the fore-arm ; the person will now 
feel that a portion of the top of the upper arm is 
swelling; in fact, there is now a compact mass of 
flesh which was not observably so prominent before, 
and which relaxes again when the arm is stretched out. 
Could we remove the skin after the arm is bent up, 
we would find a mass of red flesh, or muscle, called 
the biceps muscle. Hence, two changes will be 
discovered: — 

a. The muscle swells, 

b. It becomes harder. 

The motion of this muscle is, like all motion, the 
manifestation of a force; in the present case, the 
force of the will. The flesh, or muscle, is the carrier 
of this force. 

The above experiment shows that muscles produce 

(51) 


52 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


motion by means of their contractility. This is the 
first property of muscles. 

Contractility is the property of muscular tissue, 
by virtue of which it shortens itself. 

It is in this way that muscles move the bones to 
which they are attached. The second property of 
muscles is their sensibility. As a general thing, 
healthy muscles are not very sensitive ; witness the 
slight pain caused by a cut in the flesh. Their sensi¬ 
bility consists in this, that they can communicate to 
the mind the state and condition in which they are. 
If, for example, a muscle is fatigued, or in a state 
of cramp, we immediately become conscious of it. 
Hence, sensibility is that property of muscular tissue, 
by virtue of which it informs the mind of the condi¬ 
tion, or state, of the tissue. 

About ten minutes after death the muscles of the 
body pass, spontaneously, into a state of contraction 
very nearly like that which takes place during life. 
This produces a general stiffness of the entire body, 
and is known as the rigor mortis , or post-mortem 
rigidity. This is caused by the coagulation of the 
protoplasm of the muscle cells. 

Fat or Adipose Tissue is an oily concrete sub¬ 
stance, consisting of stearine and elaine. It is found 


THE MUSCULAR SYSTEM. 


53 


generally immediately under the skin, and in nearly 
all other portions of the body. 

In children, and in some adults, we notice this soft- 
tissue. Its chief uses are the following: — 

1st. The fat, which is situated directly beneath the 
skin, prevents much of the heat of the body from 
escaping, because fat is a poor conductor of heat or 
cold. 

2d. Fat serves as an elastic packing material in 
which to wrap delicate structures, such as the palm of 
the hand and the soles of the feet. 

3d. It serves as a store of combustible matter — 
that is, it may be burnt up in the system, and thus 
become a source of heat to the body.* 

4th. It serves to fill the cavities of the long bones. 
It is then called marrow. 

5th. It gives, together with the muscles, the full, 
round appearance, so necessary to beauty. 

The Structure of tlie Muscles. — The muscles are 
the organs of motion in the body, and are composed 
of lean meat, or red flesh. Roughly estimated there 
are about 532 in the human body, each performing a 

* Fat seems to be a sort of storage-battery to the bodily 
machine. A familiar example of the wise foresight of the 
Creator in storing the body with fat is seen in the case of 
severe illness, at which time the fat takes the place of food. 



54 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


distinct and separate office, yet all combined into 
a perfect whole. They compose the greater part of 
the flesh of the body and extremities. They are the 
active agents in the movement of the parts of the 
body upon each other, and in the movement of the 
body from place to place. 

Experiment.— Take a piece of lean meat, and 
soak it in water, washing it thoroughly. This 
process removes the blood; then the stringy, fibrous- 
like structure of the muscles can be seen. Every¬ 
one has observed how lean meat separates into rolls 
in the case of boiled corn-beef. By the use of the 
microscope, it is further made clear that the muscles 
are composed of fibres in bundles (called fasciculi), 
each bundle containing an average of about 150 
fibres. These fibres are further composed of other 
fibres called ultimate fibres , and are about 4 -^ of 
inch in diameter, having a polygonal form. These 
ultimate fibres, in turn, are made up of still smaller 
filaments, called fibrils , which have an average di¬ 
ameter of jofoo of an inch, and which contain 
about 700 to each ultimate fibre. Each fibril is 
composed of a string of small cells, or discs. A 
string with a large number of flat buttons strung 
upon it, would give a clear idea of a fibril highly 
magnified. These lines of contact of the buttons 


THE MUSCULAR SYSTEM 


55 


would represent the transverse stripes (striae), pecu¬ 
liar to muscles under the 
Other fibrils have not this 
striation. 

Description of striped muscle, 
magnified. 

1. Longitudinal cleavage. 

2 . Transverse cleavage. 

3. A disc partially separated 
from two fragments of muscle. 

4. Another disc, or cell, nearly 
detached. 

5. A magnified disc. 

6 . Fibrillse separated. 

7. 8. Fibrillse more highly mag¬ 
nified, showing the discs, or cells. 

The Muscles are Wrapped in a tissue which is 
found in nearly all parts of the body; it envelops 
the muscles, it coats the bones and cartilages, and 
thus connects the different portions of the human 
body with one another. According to its different 
uses, it varies greatly in character, being at times 
soft and tender, at other times very dense and 
strong, as e . g, in the tendons. The fasciculi * 

* The bundles, or fasciculi, are united to form larger 
bundles, and these in turn to form others. Knowing the effect 
of the small strands in a rope, one can appreciate the strength 
of the muscular tissue. 


influence of the will. 



Striped muscle, magnified. 









56 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


and ultimate fibres are invested with a thin mem¬ 
branous-like sheath of tissue of a cellular nature. 
It is called connective tissue. The fibrils have no 
such covering. 

Attachments and Tendons. —A lever is a stiff bar 
made to turn on a point, by means of which power is 
made to do work. The points necessary to apply 
this power are: 1. The power to be applied; 2. The 
point of support, or fulcrum; 3. The load to be 
lifted, or weight; all of which are respectively repre¬ 
sented by P, P, and W. These points may be used 
in three different ways termed the three classes of 
levers. For example, the following illustrations are 
given: — 

P_Q...W p □•••W y P CZ I-..W 

A -a 

F p 

FIRST CLASS; SECOND CLASS. THIRD CLASS. 

Every motion of either the body or its parts 
may be classed under one of the above kinds of 
levers. 

Experiment. — Straighten the arm and extend it 
horizontally; place a five-pound weight on the hand. 
To uphold this weight a muscular effort, or force, of 





THE MUSCULAR SYSTEM. 


57 


about 100 pounds is required, to say nothing of the 
effort to sustain the weight of the arm itself. 

Before investigating this phenomenon, the young 
student should be reminded that the human arm is a 
lever with its point of support or fulcrum, at the 
point o (Fig. 15) in the shoulder-joint; and that, in 
virtue of this joint being a ball-and-socket joint (Fig. 
15), the arm enjoys motion in a variety of direc- 


we. 



FIG. 15. 


tions; and that all these motions are exerted by 
strongly-developed muscles, extending from the 
shoulder-blade, clavicle, and thorax to the upper arm, 
to which they are attached (page 65, Fig. 17). 

The weight (Fig. 15) is supported by a shoulder- 
muscle, through which the power is exerted at the 
point b. Joining the points o, b and a (the weight) 
by straight lines, a bent lever, o b a, with fulcrum at 
o, is formed. The weight evidently operates at the 
end of the long lever-arm, o b, while the muscular 
power at b operates only by the short lever-arm, o b. 
The ratio of the two lever-arms is about as 20 to 1. 
This explains why the five-pound weight, at the end 



58 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


of the long arm, acts with a momentum of nearly 
5X20 = 100 pounds ; and why the strong shoulder- 
muscle at the end of o 5, in order to balance this 
momentum, must pull upward with a force of 
(nearly) 100X1 = 100 pounds. It also accounts for 
the fact, known to every one, that it requires exertion 
to hold the arm extended, even without any additional 
weight in the hand. 

The strong shoulder-muscle here mentioned is 
omitted in Fig. 15 because it would prevent o b from 
being seen. This muscle is the chief but not exclus¬ 
ive supporter of the weight of the ball and that of the 
extended horizontal arm ; in this it is assisted by 
other muscles, among which is the biceps — the 
muscle visible in Fig. 15. 

The lever, o b a, is a lever of the third class, the 
power being applied between the fulcrum and the 
weight. A pair of tongs with which to lift lumps 
of coal is also a lever of the third class. If, 
now, with a little imagination, we compare the 
point where the tongs are riveted together with 
the point below each ear where the jaws come 
together; and if, furthermore, we imagine each half 
row of teeth to be a lever similar to one of the 
levers of the tongs, then half of the upper jaw, 
with its lower half attached, forms a pair of levers 
like a pair of tongs. The farther to the rear the 


THE MUSCULAR SYSTEM 


59 


resistance to be overcome by the teeth be placed — 
that is, the nearer to the fulcrum — the shorter do 


we make the lever- 
weight or resistance 
effort is required. 
It follows, then, 
that the jaws exert 
the greatest force 
between the hind¬ 
most molars. To¬ 
ward the front part 
of the jaw the 
teeth lose their 
grinding power, and 
it is a wise provi¬ 
sion of nature that 
the front teeth, hav¬ 
ing but small ca- 
pacity otherwise, 
possess a knife- 
shaped form. 

Standing.— When 
the center of gravity 
of a body is sup¬ 
ported, the entire 
body is supported.; 


arm at the end of which the 
operates, and the less muscular 

FIG. 16. 

The attachments of 
some of the most 
important Muscles 
which keep the Body 
in the erect Posture. 


fc 




4 


V 


I, the muscles of 
^jU the calf; II, those of 
the back of the thigh; 
III, those of the spine. 
These tend to keep the 
body from falling for¬ 
ward. 1, the muscles 
of the front of the 
leg; 2, those of the 
front of the thigh; 3, 
those of the front of 
the abdomen; 4, 5, 
thosj of the front of 
the neck. These tend 
to keep the body from 
falling backwards. 
The arrows indicate 
the direction of action 
of the muscles, the 
foot being fixed. — 
Cyclopedia of Valu¬ 
able Beceipts. 










60 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


The center of gravity in the human body lies in 
the abdomen. In order that a person may stand 
erect, therefore, the center of gravity must be sup¬ 
ported by the legs. This requires work on the 
part of all the muscles below the trunk. The 
amount of this work is very great; this is proved — 
(1) by the difficulty which a little child experiences 
in learning to stand erect; (2) by the necessity 
which the adult experiences while standing, of fre¬ 
quently shifting the center of gravity, throwing it 
alternately over one limb, so as to allow the other 
to rest for a short time. 

Walking.— This act comprises: — 

(1) The lifting of the body . This is accomplished 
by lifting the leg; that is, by increasing the distance 
between the toes and the center of gravity. During 
this action, one leg supports the entire weight of 
the body; the other leg having at the same time no 
load to carry, swings freely forward, after the manner 
of a pendulum. 

(2) The forward motion of the body , and its subse¬ 
quent downward motion as the foot of the other leg is 
planted on the ground. 

(3) The forward swinging of the leg . The other 
leg now bears the weight of the body, while the first 


THE MUSCULAR SYSTEM. 


61 


swings freely forward. This mechanical forward 
swinging requires scarcely any muscular exertion; 
hence it affords alternate rest to each limb. 

Although the entire weight of the body is carried 
alternately by one foot, yet an hour’s walk is less 
fatiguing than to stand still for an hour, because, in 
walking, each limb enjoys alternate rest. 

Leaping is a combination of two essentially different 
motions : First , the body is lifted by the action of the 
muscles; of course, there must be a support under 
foot. Next, the feet separate from the ground and the 
body rises; gravity stops its upward motion and pulls 
it down again. Let us recall the above example. 
The first motion, viz., the lifting of the body, is 
effected by muscular action. It has a limited range, 
perhaps no more than one-half foot. Now the entire 
work, as we have seen, amounts to 300 footpounds, 
and is carried on by a muscular action through one- 
half foot of space. Therefore, the muscular action, 
that is, the entire pressure of the feet against the 
ground, while the body is moving upward one-half 
foot, in order to produce 300 footpounds of work, 
must be equal to 600 pounds, for 600 X = 300. In 
order that a person may be able to produce so great a 
pressure through the one-half foot of space, he must 
first assume a stooping position. It is the muscular 


62 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


effort required to produce this great pressure that 
makes the task so arduous. 

Tbe Muscles of the Head and Trunk perform no 
such intense labor as those of the limbs; hence, they 
are less substantial. The roof of the skull has no 
muscles proper, but a tendinous cap, or helmet, under¬ 
lying the hairy skin; it may be moved by muscles in 
the front and rear portion of the head. The muscles 
of the eye are of a very delicate structure, and so 
arranged as to roll the eye-ball, move it slightly for¬ 
ward and backward, and to raise and lower the eye¬ 
lids. The tongue, the interior of the mouth, the 
throat, in fine, all the parts of the body, have suitable 
layers or strings of muscles in order to produce mo¬ 
tion, to hold the limbs in position, and, in general, to 
protect the skeleton. The entire number of external 
muscles may be set down at two hundred and forty 
pairs. (Fig. 13). 

The Heart is a muscle which by its motion, 
propels the blood through the body. At every 
contraction of the ventricles a charge of about 
six ounces of blood is driven into the arteries. The 
great velocity imparted to the blood, and the fact that 
during life the motions of the heart are carried on in 
never-ceasing successions—the heart, like the lungs, 


THE MUSCULAR SYSTEM. 


63 


never rests while the vital processes are in function — 
render it, beyond doubt, that the heart inces¬ 
santly performs an enormous amount of work. 

Muscles Remain Contracted only for a short period. 
They soon relax, and during relaxation their previous 
strength is regained. In walking, the muscles are 
constantly changing from contraction to relaxation, 
while the erect position of the body requires the ac¬ 
tivity of all the muscles; for those muscles which are 
situated in front prevent the body from inclining 
backward, while those behind prevent the body from 
bending forward. The muscles upon the sides of the 
body act in a similar manner. This explains why to 
stand erect and motionless for a given time is much 
more tiresome than to move about during an equal 
length of time. We gather new strength when we 
rest or sleep ; complete rest is found only in a lying 
position. 

When a Force Performs Work, the work is always 
a motion of some kind or other. The force of the 
will or mind, when imparted to a muscle, causes the 
muscle to perform work which, for the greater part, 
consists of motion. Motions produced by the human 
body are utilized mainly because of their being con¬ 
verted into force when they are suddenly arrested. 


64 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


The blacksmith, having impacted motion to his ham¬ 
mer by lifting it, changes this motion into force when 
the hammer strikes the iron upon the anvil. If the 
weight of the hammer = 3 pounds, and the height of 
its descent = 4 feet, the work performed by the per¬ 
son is 3 X 4 = 12 footpounds. (A footpound is a 
pound lifted through one foot of space against 
gravity.) But this does not tell us anything about 
the quantity of muscular exertion. Perhaps the fol¬ 
lowing instance will make it clearer: If an adult 
weighing 150 pounds wishes to leap two feet high, 
the amount of work = 2 X 150 = 300 footpounds. 
On an inclined plane, or stairway of gentle slope, 
this amount of work is performed easily in one or 
more seconds. But to do it by jumping seems to 
require a greater effort, although the amount of work 
performed remains the same. 

The experience of a long period of years has 
shown, beyond doubt, that the mechanical power of 
the human body is used to best advantage by both 
employer and employee when the work is done regu¬ 
larly and continuously, not in separate, fitful exer¬ 
tions. Man’s forces must not be exhausted further 
than rest and food can replace them day by day. In 
utilizing our physical forces, therefore, certain limits 
must be observed, a limit of exertion as well as a 
limit of time. Any deviation has always been fol- 


THE MUSCULAR SYSTEM. 


65 



lowed by a deterioration in the value of the work 
done. 

From the preceding it would 
appear that a large amount of 
muscular force exerted by a hu¬ 
man being during the day is 
wasted; but we must remind 
ourselves that much of the force 
apparently lost is realized as 
a gain of time, a convenience of 
direction, and as a greater range 
of motion. 

Tendons. — It should be 
stated here that nearly all mus¬ 
cles terminate at their ends, 
where they are attached to 
bones, in sinewy, inelastic cords, 
called tendons. Tendons form 
the connecting link between 
muscle and bone, just as liga¬ 
ments between bone and bone. 

When the extremity of the 
bones presents a broad surface 
for attachment, the tendon is 

Hand, arm, and shoul- 
broad accordingly ; but should de r, showing tendons. 

the place of attachment be small, fiq. 17 


66 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


the tendon accommodates itself to the circumstances. 
The tendons combine to give strength and beauty 
to the limbs, which, without the compactness of 
these inelastic cords, would be clumsy and un- 
wieldly. The tendons* and muscles unite firmly 
and smoothly. The tendons are composed of 
dense areolar tissue. 


The largest tendon in the 
body is the tendon of Achilles, 
in the heel. The strength of the 
tendons is wonderful. It is said 
that the tendon of Achilles will 
hold up a 1000-pound weight. 



Tlie Kinds of Muscles.— There 
are two kinds of muscles, dis¬ 
tinguished by their structure and 
mode of action: first , the volun - 


tary muscles, as the biceps and 
lower portion or the leg: nearly all the muscles used for 
FIG * 18, moving bones. The action of 

voluntary muscles is, to a large extent, controlled 
by the will. Second , the involuntary muscles, as 


* The arrangement of the tendons in moving the fingers may 
be nicely shown by taking the leg of a chicken, one tendon 
moving one toe, and another tendon, another. 



THE MUSCULAR SYSTEM. 


67 


in the trachea, the bronchi, and the digestive canal. 
The non-striped, or involuntary muscles, are found 
in the walls of the hollow viscera; that is, the 
stomach, intestines, bladder, etc., as well as the walls 
of the air tubes, gland ducts, blood and lymph ves¬ 
sels, the skin, and mucous membranes. These muscles 
are beyond the control of the will. Thus, whether 
we will or not, the process of respiration goes on day 
and night. The roughness of skin, called goose skin , 
is caused by the action of involuntary muscular fibres 
in the skin. It is usually the result of cold, elec¬ 
tricity, or sudden mental impressions. Some muscles 
are both voluntary and involuntary, as those of the 
eye-lid, while the muscles controlling respiration are 
voluntary only to a certain extent. 

The voluntary muscles may be classed as animal, 
or striated ( striped), while the involuntary may be 
termed organic, or unstriated (non-striped). The 
striped structure was discussed in a former para¬ 
graph. One marked exception to the rule, that all 
striated muscles are voluntary , is the heart, which is 
an involuntary muscle, although transversely striped. 
Notwithstanding that the heart is purely involuntary 
in its action, there have been cases recorded of per¬ 
sons who could control the beating of their hearts. 
However, such cases are rare. 


68 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Muscles are also Classed according to their form, 

as radiate , fusiform , penniform , orbicular , ribbon¬ 
like and cord-like . 

The Arrangement of the muscles is very simple, 
they being arranged in pairs. The two sides of the 
body are alike. For every muscle producing a 
certain motion, there is another muscle producing an 
opposite motion. This can be easily tested by 
alternately raising and lowering the fore-arm. This 
arrangement admits of a multiplicity of movements. 
The variety of movements in the case of the human 
hand is inconceivable. With the wonderful disposi¬ 
tion of the 532 or more muscles of the body, man 
becomes God-like in his physical powers. In 
muscles there is as much diversity in the size as 
there is in the variety of motions. The longest 
muscle, sartorius , is over eighteen inches in 
length, while the smallest is the stapedius , a 
muscle of the ear, which is only one-sixth of 
an inch in length. 

2. THE USES AND FUNCTIONS OF THE 
MUSCLES. 

The Muscles not only add to the beauty of form 
and outline of the body, but they make possible its 
vast number of motions. They are the active 
agents of motion as well as locomotion. To appre- 


THE MUSCULAR SYSTEM. 


69 


ciate the effect of the muscles with other flesh 
tissue intact upon the frame-work of the body, 
examine that same frame-work without the soft tis¬ 
sue ; that is, the human skeleton, the very name of 
which almost strikes terror. To appreciate the 
variety and beauty of movements, made possible 
by the intricate muscular arrangement, notice the 
graceful dancer whirling away through the waltz; 
the hands of the skillful performer upon a musical 
instrument, bringing forth sweet melody; or the 
rapid and delicate touches by which the artist por¬ 
trays a living landscape to your wondering vision ! 
Whether it be the laborer wielding his heavy sledge, 
or the prima donna trilling the variations of a 
sonata, the same unerring laws must be followed ! 

The discussion of the motion and use of each 
muscle belongs to the higher study of this sub¬ 
ject, yet it is interesting to know how the bicejps 
raises the fore-arm ; how the gastrocnemius , plan - 
laris, and soleus, of the back part of the leg, assist in 
walking, and standing upon tip-toe; how the famous 
sarlorius assists the tailor in throwing one leg across 
the other; how the great psoas muscle bends the 
thigh upon, or towards the body; how the inlercos - 
tals raise the ribs; how the diaphragm enlarges the 
chest cavity, and how the masseter and temporal move 
the lower jaw. When we consider that there are 


70 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


about 532 muscles, we can imagine what a complex 
subject the mastery of all their uses and motions 
would be. And yet how necessary to man’s highest 
development are all these movements! However, a 
few suggestions on muscular development will be 
helpful. 

Muscular Development and Exercise. —All liv¬ 
ing things must do, in order to remain in health, 
what the Creator intended them to do. The fish must 
swim, the bird fly ; so, also, must man, who is the 
highest of the animal creation, perform many com¬ 
plex duties that he may fulfill the laws of his being. 
His limbs, stomach, nerves, and mind must attend to 
their appointed ends. 

Observation.— Tie an arm to your side, and in a 
few months it will waste away to skin and bone. In 
the same way the brain from a lack of use will 
become incapable of strong, healthy action. 

Exercise makes the muscle grow larger, darker, 
and more solid. Notice the huge strong muscles of 
the blacksmith or prize-fighter, as compared with the 
soft, pale, flabby tissue of the clerk who sits for 
hours with neither manual labor nor exercise. 

Many occupations tend to give all the parts of the 


THE MUSCULAR SYSTEM. 


71 


body their necessary use. Farming is mentioned as 
one of these, and such occupations tend to long, 
happy lives. 

A rule of exercise should be: Let the kind of 
exercise be selected that will bring into use muscles 
that were not used while at our accustomed employ¬ 
ment. If we sit at our work, let our exercise in 
recreation be walking, riding, etc., while if we use 
our lower limbs much in our calling, let the upper 
part of the body be correspondingly trained. 
Plenty of muscular exercise should be followed by 
mental training, and vice versa. 

Another law in exercise should be: Always stop 
before you feel tired. Excessive or violent exercise 
is very unwise and injurious. Long-continued or 
violent exercise often produces death. 

No school, of whatever kind, is now complete with¬ 
out a systematic, thorough, careful course in physi¬ 
cal training. Half the energy of pupils is wasted 
by over-study and under-exercise. How necessary 
to keep the house—the human body — as well as 
the inhabitant —the mind — in good condition ! 

Why Exercise Should Be Taken.— 1. The im¬ 
mediate effect is strengthening and enlarging the 
muscles, which form such a large proportion of the 
body. 


72 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


2. It causes the blood to flow more freely through 
the muscles and incites the lymphatics to action, 
thus making them more active, and refreshing the 
whole body, stimulating all the organs. 

3. Exercise develops the whole body harmoniously, 
so that each part may bear the strain necessary to 
allow every other part to do its proper work. Noth¬ 
ing is more beautiful than the fully-developed, well 
rounded, elastic, hardy human form — the crowning 
glory of the Creator’s work. 

4. Exercise prevents crooked limbs, spine curva¬ 
tures, weakness, sickness, mental disorders, while it 
vastly increases the individual’s capacity for labor. 

5. It frees the body from waste matter. 

Kinds of Exercise. — There are so many varieties 
of beneficial forms of exercise that it seems needless 
to name any. Yet, we mention these: Walking, 
riding, rowing, bicycling, tennis, croquet, etc. This 
may be taken as a guide in selecting the kind, that it 
he an active , outside , general exercise , pleasing to the 
one who takes it. Inside exercise is better than none. 

How Contraction Takes Place. — Some physiol¬ 
ogists have taught that the contraction of the 
muscle is due to a peculiar position of the fibrils, 
but it is now definitely determined that it is due to a 


THE MUSCULAR SYSTEM. 


73 


state of the little cells, or discs. By the use of the 
microscope it has been learned that, in a state of 
contraction, each little cell thus affected shortens 
itself in the direction of the fibres, while at rest 
the cell has its greatest diameter parallel to the 
direction of the fibre. This contraction begins at 
one end of the fibre, and passes step by step to the 
other end, thus exercising only a part at one time. 
How the energy (that passes along the nerves to 
secure the action) does its work, is a mystery. 

Muscular fibre has the property — Contractility — 
of shortening itself when a stimulus is applied. 
These stimuli have been mentioned elsewhere. The 
irritability and tonicity* of muscular fibre are 
dependent upon nervous or vital force. If the in¬ 
fluence of either nervous or vital energy be cut 
off, the irritability and tonicity will cease in a 
short time. 

Muscular Contraction is very rapid. The heart 
pulsations in children have been known to be nearly 
two hundred per minute, while persons can pro- 


* Some writers upon the subject of physiology name the above 
property of muscles, which they call tonicity . Tonicity is a con¬ 
stant strain of the muscular fibre. It is this property which pulls 
a cut, or gash, wide apart. It makes the muscles ready for action. 
It might be termed the life of the muscle. 



74 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


nounce eight times that many letters per minute. 
The number of contractions to produce a musical 
tone must reach a very large number per second. 

The Strength of muscular fibre is beyond compre¬ 
hension. Men have been able to take in their teeth a 
barrel of flour—196 pounds in weight—by the 
chime, or ends of the staves, and throw it over their 
heads. You remember Milo of Crete, who killed an 
ox with his fist, and then carried the animal 200 yards. 
Milo saved the celebrated philosopher and teacher, 
Pythagoras, by supporting a fallen roof until they 
both could escape. 

The Muscular Sense is the sensation of weight 
which we feel in lifting a body and which we compare 
with similar sensations in lifting another body. This 
sensation may be highly cultivated. Bank tellers read¬ 
ily detect a spurious coin by this power. This sense 
is brought into use in many of the movements of the 
body, and is very helpful to man. 

Important Facts — Muscles need rest. _The 

period of rest must be sufficient to enable the muscles 
to regain their tonicity. Constant moving allows the 
muscles to rest. However, sleep is the only rest 
which will restore vigor and life to the muscles. 


THE MUSCULAR SYSTEM 


75 


REVIEW QUESTIONS. 

1. What is the biceps muscle? What is the muscle usually 
called? 

2. What two changes take place when the muscles act? 

3. What is motion? Define contractility. 

4. What is sensibility? What is rigor mortisl 

5. How soon after death does it set in? What causes it? 

6. What is fat, or adipose tissue? At what stage in life is fat 
generally found? 

7. What effect has fat upon the bodily temperature in winter? 

8. Name several uses of fat. What is meant by storage- 
battery? 

9. Define muscle. How many muscles in the body? 

10. What is wonderful about the uses of the muscles? 

11. Explain how the structure of muscular tissue may be 
shown. 

12. Explain the relation of ultimate fibre to fibrils. 

13. Describe the form and thickness of ultimate fibres. 

14. Also, tell all you can about the filaments, or fibrils. 

15. What are fasciculi? What makes a muscle so strong? 

16. Explain how the ultimate fibres and fasciculi are protected. 
What is the covering called? 

17. What is the structure of a fibril? How illustrated? 

18. Define lever. What points are necessary in the lever? 

19. Explain by means of a stick and brick the three classes 
of levers. 

20. Name the kind of lever, and locate the fulcrum, power, and 
weight in each: 1. Standing on tip-toe; 2. Bending the trunk 
backwards; 3. Masticating food; 4. Raising the leg forward; 5. 


76 


ANATOMY, PHYSIOLOGY, AND HYGIENE 


Bending the lower leg backwards; 6. Lifting an object with the 
toe. Give other examples. 

21. Give several uses of the muscles. 

22. How may one appreciate the benefit of the muscles as a 
clothing for the bones? 

23. How may we appreciate their variety of movements? 

24. In what way are muscles subject to law? 

25. Why is it not practicable to study the motion and use of 
each muscle? 

26. Name several prominent muscles, locating them. 

27. What has been advanced by some physiologists as the cause 
of muscular contraction? 

28. What is the true theory of this? Explain it. 

29. Define contractility. Describe another property of 
muscles. 

30. Upon what does irritability and tonicity depend? 

31. Explain how rapid muscular contraction is. 

32. Give some examples of the strength of muscular fibre. 

33. What do you know of Milo of Crete? Of Pythagoras? 

34. Explain what is meant by muscular sense. Give some ex¬ 
amples of its benefits or uses. 

35. What relation do you observe between living things and 
“ their appointed end ?” 

36. State different effects of exercise upon muscular tissue. 

37. Name some occupations that tend to give work to all the 
muscles. 

38. Give the rules on exercising. 

39. What should every school have for this purpose? 

40. State the effects of exercise upon the muscles. 

41. Name several kinds of exercise. 

42. How should one rest? Should exercise be regular? 


THE MUSCULAR SYSTEM 


77 


BLACKBOARD OUTLINE. 


1. The muscles and Fat. 


T^LE MUSCLES. 


a. Experiment and Definition. 


Muscles. 


Fa-t.- 


\ Contractility, j Ma&Fl'rmer. 
(.b. Properties. -( Sensibility, or Irritability. 

I Tonicity. 

(.Rigor Mortis. 

Definition. Location. 

{ Keeps the Heat in the Body. 

Protects the Delicate Structures. 

As a Storage-battery of Heat. 

Fills the Bone Cavities. 

(.Adds to Beauty. 

The Structure of Muscles. 

( Number. 

a. General Facts. ^ Greater part of the Body. 

Agents of Movements. 


b. Uses. 


f Rolls. 

J Fasciculi. 

b. Tissue. 5 Ultimate Fibre. 

(.Fibrils. 

The Muscles are Wrapped. 

( Skin. 

a. Connective Tissue. < Mucous Membrane 
( Fascia. 

Attachments and Tendons. 

c First. 

a. Classes of Levers < Second. 

(Third. 

b. Experiments. 

Walking. 

c. Movements. ■{ Leaping. 

d. Muscles Remain Contracted 

e. When a Force Performs 


(How Related, and 
{ How Illustrated. 


Standing. 


( Center of Gravity. 

< Muscles at the Back. 

( “ in Front. 

C Lifting of the Body. 

<J Forward Motion of the 
Body. 

Head and (.Swinging of the Leg. 
Trunk. 


Work. 

Tendons. 

a. Definition and 

Attachment. 

b. Uses and Com¬ 

position. 

The Kinds of Muscles { 
The Arrangement — 

In Pairs. 


L Heart. 


I, 


According to Structure [ Vol ef r t |! l r t L Animal, or 
and Appearance.... < i nvolunlary ’_ Organic, 
(. or Unstriated. 

{ Radiate. 

| Fusiform. 

According to'Form ...A S^biculaT' 

2. The Uses and Functions. Ribbon-like. 

f To produce Motion. [ Cord-like. 

tt q J To hold the Limbs in Place, 
a. uses. ^ rji 0 p ro tect the Bones and Delicate Organs. 

(.To add to the Beauty of Form. 

f Their “ appointed end.” 

| Experiment. 

f Development and Exercise <{ Exercise — Occupations. 

I I Rules of Exercise. 

(.Gymnasia, 
f Theory. 

b. Functions. I How Contraction Takes | I^Vvof 
Place. 


l 

3. Important Facts. 


Strength of. 

I The Muscular Sense. 
(.Why Exercise. 








IV. 


THE SKIN, HAIR, AND NAILS. 

Behold the grosses of the held! the fishes of the seal the 
fowls of the air I Infinite Wisdom hath enveloped them in their 
own appropriate coverings, conserving destined ends! 

So man, "a little lower than the angels," hath been 
clothed in a wondrous garment, guarding the numberless door- 
wags of the busy laboratories within, firm and enduring as the 
magic cloak of old, flexible and elastic as the far-famed prod¬ 
uct of India's priceless tree, living get dead, dead get living, 
soft and delicate to the touch, and beautiful to the eye, Mil 
this is the human skin, the highway to the soul of man, whom 
Bod hath thus adorned with rich raiment and a crown of 
glory ,— Luc key, 


(79) 









IV. The Skin, Hair, and Nails. 


1. Introduction.— Clothing not only protects the 
body, by keeping out the heat and cold, but it also 
enables us to come in contact with things around with¬ 
out injury or inconvenience. In the same manner, 
the skin protects the soft, sensitive flesh from contact 
without. Were the skin removed from the body, the 
contact of the bare flesh with even the atmosphere 
would be agonizing. Hence, the 3kin is not only a 
soft, pliable, firm, and elastic covering for the body, 
but it is an ornament as well, pleasing to the eye. 
These are only a few of the duties of this most im¬ 
portant element of the system, as the skin is the chan¬ 
nel through which the body daily relieves itself of a 
large amount of effete matter, adding greatly to health 
and comfort. 

2. Structure of the Skin.— The skin is the exter¬ 
nal covering of the body. It consists of two layers — 
the outside skin, the epidermis , or cuticle , also called 
scarf-skin, and the inner one or dermis , called cutis 
vera , true skin. 

ti 


(81) 


82 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


The Epidermis contains coloring matter, which 
gives rise to shades of tint in the skin of both individ¬ 
uals and races. The coloring is developed by expos¬ 
ure to the sun. The more the skin is subjected to 
friction and pressure, the more does it grow — that 
is, the more does it become thick and horny. 

The epidermis serves to protect the sensitive lower 
skin, or dermis, and to moderate the evaporation of 
fluid from the blood vessels. 

These two layers, cuticle and cutis vera , are very 
closely united, yet their separation is clearly shown 
when a blister is produced upon any part of the 
body. A watery fluid gathers under the epidermis , 
which is shown to be a thin, white membrane, 
devoid of feeling and blood. It is made up of 
round-like cells, which become flattened at the upper 
surface, and drop off in scales. This is exempli¬ 
fied in the case of the scalp, whose cast-off scales are 
called dandruff. The epidermis renews itself upon 
the under surface. This part of the skin varies in 
thickness on different parts of the body, and bears 
the same relation to the inner skin, cutis vera , that 
the external bark bears to the inner, living bark, of 
the tree. The cuticle upon the face is only about 
1000th of an inch in thickness, while upon the soles of 
feet, it reaches l-12th of an inch. In composition, the 


THE SKIN, HAIR, AND NAILS. 


83 


epidermis is albumen — the same as the white of an 


egg. 


The Dermis, or cutis vera , lies below the surface, 
is the true skin, and invests the arteries, veins, 
lymphatics, nerves, sweat and oil glands, being the 
origin and support of the epidermis. It is firm and 
elastic, these properties being due to the presence of 
muscular fibre. Its extreme sensitiveness and 
vitality may be ascertained by inserting a fine needle 
into the tissue. This part of the skin is made up of 
white and yellow fibrous tissue. The upper surface 
of the dermis is covered with little protuberances, 
called papillce , which contain these nerves and 
blood-vessels. 

The lower part of the dermis contains the sweat 
glands, whose outlets through the epidermis are called 
pores . Here lie also the oil glands. 

Glands.— The secretions of the skin consist of 
two different fluids; one oily, the other watery. 
The oily one is secreted mostly in the scalp and 
the face, where the skin is largely supplied with 
hair. The other is called perspiration , or sweat , the 
two terms being habitually taken synonymously, al¬ 
though there is this difference between them: Per- 


84 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


spiratioii is an insensible excretion, which evaporates 
on the skin; sweat is a sensible secretion, composed 
of the same fluid as the other, but appearing on 

drops. The passage of 
these fluids is affected 
by a multitude of fine 
canals, or pores (Fig. 
19) in the skin. Per¬ 
fect health requires 
cleanliness, so that the 
activity of the pores 
shall not be impeded. 

The quantity of water 
lost by transpiration de¬ 
pends, like all evapora¬ 
tion in the open air, upon 
the temperature, the 
saturation, and the still¬ 
ness of the atmosphere. 
In hot weather the quan¬ 
tity of excretion from the skin is greater than in 
cold. When the atmosphere is fully saturated with 
watery vapor, perspiration does not evaporate ; and 
the consequence is an almost insufferable sensation 
of heat. The same holds true when, owing to the 
absence of currents of air, the watery vapors of 


the skin in the form of 



-Epidermis. 


Dermis. 


Glands for 
the Hair. 


Perspiration 

Glands. 


Hair. 


fig. 19. 

Sectional View of the Human 
Skin, Highly Magnified. 




















THE SKIN, HAIR, AND NAILS. 


85 


perspiration remain around the person instead of 
being constantly displaced by fresh; that is, less 
saturated air. 

Connective Tissue. — A piece of fresh animal 
skin, put into water, will swell up without dissolving. 
If now the skin be boiled in the water for several 
hours, most of it will dissolve, and on allowing the 
liquid to cool, a gelatinous substance is obtained. 
When dried, this forms the well-known glue. Nearly 
all connective tissue yields the same result if 
treated in a like manner. 

3. Hair and Nails. — These are forms of the 
epidermis. 

The Hair and Nails are peculiar forms of the 
epidermis. The latter are composed of horny scales 
and cells, closely packed together. The root of a 
hair, together with the root-sheath in which it is 
imbedded, may be seen when a hair is pulled out. 

The Hair not only protects the head from heat 
and cold, but it is a safeguard against injury, as 
well as being an ornament. A hair consists of root, 
shaft , and point. Hair is found on nearly all parts of 
the body, excepting the palms of the hand and the 


86 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


soles of the feet. In composition a hair has three 
parts: an epidermis ^ a fibrous part, and a marrow « 
lilce center. The epidermis is in scales, overlapping 
one another like the shingles on a roof. Each hair 
is formed upon the apex of a papilla. The color is 
thought to be due to the presence of iron in the hair. 
Hair is very elastic, stretching nearly one-fifth its 
length. It is dry and harsh or moist, according to 
the condition of the skin. The hair grows rapidly, 
faster by day than by night, and in summer than 
in winter.* 

The Nails are very useful and ornamental. By 
means of them our fingers and toes are protected 
and we can perform many little motions that other¬ 
wise would be impossible. Besides they add so 
much to the beauty of the fingers and toes. The 
nail grows from an underfold of the cuticle , of which 
it may be considered a continuation. As the nail 
grows, it is pushed out, starting from a groove-like 
root, called the matrix . The nails, uidike the 
hair, have blood-vessels. The Chinese have the 


* The number of the hairs varies with the color and portion 
of the body. In one case there was found on the same surface 
147 black hairs, 162 brown, and 182 blonde. On a surface one- 
fourth of an inch square the same author found on the scalp 293 
hairs and on the chin, 39.— Hitchcock. 




THE SKIN, HAIR, AND NAILS. 


87 


habit of allowing their nails to grow sometimes as 
long as two inches. A nail will grow its whole 
length in about 15 weeks, on an average.* The nails 
should be carefully pared with a sharp knife, but 
never scraped on top. 

Nails grow, like hair, by the constant addition of 
cells from beneath and behind, which take the place 
of portions worn away or cut off. 

4. Functions and Hygiene of the Skin, 
Hair, and Nails.— The Skin prevents absorption, 
because the lymphatics terminate in the dermis, 
this being separated from the external world 
by the epidermis. It will be readily observed 
that this arrangement prevents the absorption 
of injurious liquids brought into contact with 
the body. However, there is absorption through 
the skin, and poisonous cosmetics, washes, and hair- 


* “ To show the duration of life in one kind of cell, let us 
turn to the human nail. The latter, growing from a furrow of 
the skin, is made up of skin-cells. In the depth of the furrow, 
youth prevails; at the upper margin — which we trim — old age. 
Berthold proved that a nail-cell lives four months in summer 
and five in winter. A person dying in his 80th year, has changed 
his nail 200 times at least — and the nail appeared such an inan¬ 
imate, unvarying thing! No other cells, we believe, have a life 
nearly so long as that of the nail .”—Compendium of Histology 
by Heinrich Frey. 



88 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

dyes should be avoided. There have been cases 
where patients have been saved by absorbing stimu¬ 
lants through the skin, when the proper channels 
were not in a condition to perform their customary 
functions. 

Again, the impenetrable epidermis, or scarf-skin, 
prevents excessive perspiration, which would work 
harm to the system. Owing to a peculiar arrange¬ 
ment of the mouths of the pores, perspiration takes 
place under a stimulated condition of the body. 

By means of the oil glands, the skin is kept soft 
and pliable, while the hair is rendered flexible and 
elastic. In consequence of the oily surface of the 
skin, water will not adhere to it, while the eye and 
the ear are kept in their proper condition by this oily 
exudation. Hence, it is seen how important the skin 
is in the economy of the human body, keeping its 
balance and regulating its temperature. 

The Care of the Skin is most important to health. 
Were not the skin kept free from impurities, which 
obstruct the passages of the sweat glands, serious 
results would follow ; such as headache, fever, colds,* 


* All are familiar with the incident which happened at the 
coronation of one of the Popes about 300 years ago. A little boy 
was selected to represent an angel, being encased from head to 



THE SKIN, HAIR, AND NAILS. 89 

etc. Hence, nothing but absolute cleanliness and 
vigor will restore the health of the skin, which may 
be secured by frequent baths, rubbings, and 
exposures to the air, of the covering of the body. 

Bathing is important. One should, in warm and 
temperate climates, bathe daily in moderately cool 
water, with a hot soap-suds bath at least once a week, 
to remove the scales of the cuticle and the dry, solid 
portions of the perspiration. Only persons of vigor¬ 
ous health should take these daily baths in cold 
water. The water should be 75° Fahrenheit. Sea 
bathing is invigorating not only from the saltness of 
the water, but from the excitement consequent upon 
the environments of a well-appointed resort. This 
paragraph may be appropriately closed with a 
thought from a well-known scientist. The civiliza¬ 
tion of a country is high to that degree in which soap 
is used. May it not be added that this is also true 
of individuals. 

How and When to Bathe. — With the water at 
the proper temperature, do not remain in the bath 
too long, as the functions of the skin are partially 
arrested while bathing. When coming from the 


foot with gold-leaf. In a short time, he fell sick, and every thing 
but removing the gold-leaf, was done. Of course he died. 



90 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


bath, vigorously rub the body with a coarse towel 
until a ruddy glow sets in. This bright, ruddy ap¬ 
pearance is a sure test of the good effects of the 
bath, and is produced by the rushing of the blood 
from the interior to the surface of the body — an 
effect called reaction . Beware of the dark, blue 
condition of the skin brought about by bathing in 
too co4d water or remaining in too long. Should 
such a condition as the last prevail, take a stimu¬ 
lant, exercise vigorously, and clothe the body as 
quickly as possible. When this effect of the bath 
prevails, the blood has set toward the heart 
and interior of the body. Reaction must be 
secured. 

As to the Time of Bathing, select any time ex¬ 
cept upon an empty or a full stomach, or when the 
body is heated or exhausted . Although nothing is 
more beneficial to an exhausted person than a hot 
bath. The habit of taking a cold bath immediately 
after rising is a good one. It should be taken quickly 
in order to secure good results. The shock to the 
nervous system is excellent. 

The Body Should Be So Clothed that one feels 
comfortable, neither too cold nor too warm, in 
winter and in summer. One’s comfort is a 


THE SKIN, HAIR, AND NAILS. 


91 


good test of how much to wear in the different 
seasons.* 

5. Important Facts.— The Skin daily throws off 
about two pounds of fluid matter, which passes away 
by means of the sweat glands. 

It is interesting to know that these glands are about 
tV of an inch in thickness and their tubes about 
tJ-q- of an inch in diameter, while the length of the 
tube is about \ of an inch. There are about 2,500 
pores to the square inch on the human body, and 
the amount of surface upon a person of ordinary size 
is 2,500 square inches. These tubes in the skin laid 
end to end would make many miles in length. 

It is generally supposed that coloring matter is 
found in the skin of all persons. However, this is 
not always the case. Albinoes have no pigment in 
the epidermis; hence this accounts for their most 
peculiar appearance. 

If the dermis be injured or torn off, the wound will 
never be covered with skin so permanent.t Yet, 


* Only fools and beggars suffer from the cold;.the latter not 
being able to get sufficient clothes, the others not having the 
sense to wear them.— Boerhaave. 

f The skin is not a permanent sheath, but is, as it were, 
always wearing out and rubbing off, and new skin is always ris- 



92 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


modern science has reached such a degree of perfec¬ 
tion that large pieces of the integument have been 
transferred from one person to another and made to 
grow. This process is called shin-grafting , and is an 
ordinary matter among surgeons of the present day. 

The Hair is very glossy in health, and grows in 
length only. The longest and coarsest hair is found 
upon females. That the hair is not easily affected by 
external influences is shown in the examples of mum¬ 
mies, thousands of years old, whose hair was still 
intact when found and even retained its color. A 
hair will sustain the weight of several ounces. 

The Nails grow very slowly. Should a nail be 
removed by accident, it will be replaced by a new 
one, provided the root is still uninjured. By filing 
a small notch at the root of the nail, you can 


ing up from underneath. A snake leaves off his whole skin at 
once, as we leave off a suit of clothes or a dress, and sometimes 
we may find his whole cast-off covering turned inside out, just 
as he crept out of it. In man, generally, we do not notice the 
dead particles of the skin as it wears off; but where the cuticle 
is pretty thick, as on the soles of the feet, we can see it peel off 
in little rolls whenever we wash the feet in hot water. After 
scarlet fever, too, sometimes the dead skin comes off in great 
flakes, and from the hands almost like the fingers of a glove.— 
Berners. 



THE SKIN, HAIR, AND NAILS. 


93 


observe how fast the nail grows as it nears the end of 
the linger. 

Disorders of the Skin, Hair, and Nails.— Proud 
Flesh is an unnatural, florid growth of a granulated 
form, growing in wounds or sores. It is caused by 
keeping the wound too warm or it may result from a 
weakened condition of the system. 

Treatment .— Powdered calomel will check this 
growth, which will usually succumb also to powdered 
burnt alum. 

Warts are unnatural growths of the papillae. 
They give a repulsive appearance to the hands, or 
other portions of the body, and should be removed. 

Treatment .— Apply to the wart, with a small 
brush, some aqua fortis , being careful not to let it 
touch anything but the wart. In a few days this 
application will kill the growth, so that it may be 
pulled out by the roots. 

Corns are thickened, calloused portions of the 
epidermis, caused by constant friction. 

Treatment .— Soak the calloused place daily in hot 
water, and remove the corn or thickened cuticle by 
paring or rubbing with a pumice-stone. 

Continue this, and wear comfortable shoes, in case 


94 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


of a corn on the foot, and the most obdurate corn 
may be removed. 

An Ingrowing Toe-Nail is a very troublesome 
thing, and may be a dangerous one. 


Treatment. — Force lint 
under the nail to raise it up 
out of the flesh. This is to 
be done after the toe has 
been soaked in hot water 
to draw out the soreness. 
Then scrape a furrow down 



Ingrowing Toe-Nail . 
fig. 20. 


lengthwise through the nail, ending in a little V- 
shaped notch at the end. Continue this scraping 
daily, and wear shoes that do not compress the nail. 
This treatment will cure aggravated cases of in¬ 
growing toe-nail. Proud flesh may be removed by 
putting on powdered perchloride of iron or dropping 
hot tallow upon the sore part. 

Dandruff (Furfura) is nothing more than scales 
of the epidermis, which are present on all parts of 
the body, but more noticeable on the head because of 
the contrast with the hair in color. 

Treatment .— Daily remove the dandruff with a 
stiff hair-brush. The friction of the head excites 
the epidermis to healthy action. The hair should 


THE SKIN, HAIR, AND NAILS. 


95 


be washed weekly in strong soapsuds and then 
thoroughly dried. Care must be taken here or cold 
will result. Little or no oils should be used upon the 
hair, as the natural oil of the hair is sufficient. Bald¬ 
ness results from sickness, especially fevers. In case 
of falling out of the hair, wash the head daily in salt 
water with a little ammonia added, and then rub the 
head vigorously. Also cut the hair off, if there be a 
disposition to come out. 

Chilblains are an itching, inflammatory condition 
of the hands, feet, etc. It is caused by a diseased 
condition of the skin and muscular tissues. 

Treatment . — Keeping the parts affected at even 
temperature, avoiding very great extremes of cold. 
Do not have the parts affected compressed. At night 
rub upon the diseased parts a mixture of lard and 
mustard, thoroughly drying before a fire. Slacked 
lime, moistened with oil, well rubbed on, is a good 
remedy. 

Eczema, commonly termed Salt Rheum, is an 
eruption erf minute vesicles, closely united and run¬ 
ning into one another, so as to form a moist sore. 


96 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


REVIEW QUESTIONS. 

1. Name several uses of the skin. 

2. Why would contact with the outside world “be agonizing,” 
were the skin removed? 

3. How many layers in the skin? Name them. Give the 
different names for the outside layer. 

4. Where is the coloring matter? What thickens the skin? 
Where would you be likely to find thickened skin? 

5. How is the separation of the dermis and the epidermis 
shown? 

6. Explain the structure of the epidermis. Of the dermis. 

7. Explain the cause of dandruff. How does the epidermis 
grow? Where does it decay? 

8. Tell where the skin is thick and where thin. 

9. What is the composition of the epidermis? 

10. What are invested by the dermis? 

11. What makes the dermis firm and elastic? 

12. How may its sensibility be determined? 

13. What are the offices of the sweat and the oil glands? 

14. Explain the difference of the products of the sweat glands. 

15. What promotes the activity of the pores? 

16. Upon what does the quantity of water lost by transpiration 
depend? 

17. When does the perspiration not evaporate? 

18. What commercial product is derived from connective 
tissue? How is it obtained? Name the kinds of connective 
tissue. 

19. Name two special forms of the skin. 


THE SKIN, HAIR, AND NAILS. 


97 


20. Give the uses of each. Explain the structure of each. 
Give the parts of the hair. Where is hair found? 

21. What causes the color of hair? When does it grow most 
rapidly? Tell something about the number of hairs. 

22. How does the nail grow? What is the matrix? 

23. What nationality of people have long nails? 

24. How long does it require for a nail to grow out? 

25. Show the duration of life in one kind of cell, by taking the 
nail as an example. 

26. How should nails be treated? How do they grow? 

27. How does the skin prevent absorption? 

28. What benefit in this, regarding poisons and stimulants? 

29. How is excessive perspiration prevented? 

30. What does the oil do for the skin and hair? 

31. Why should the skin be kept clean? 

32. Relate the incident of the boy at the Pope’s coronation. 

33. Why should we bathe often? What should the temperature 
of the water be for ordinary bathing purposes? 

34. Explain how and when to bathe. 

35. What is reaction? What is opposite to reaction? What 
must be done when reaction does not set in? 

36. What is a good rule for clothing one’s self? 

37. Tell what Bo^rhaave says about clothing. 

38. How much perspiration daily passes off through the skin? 

39. Give the different dimensions of sweat glands, their num¬ 
ber, etc. 

40. What is skin-grafting? Tell what Berners says of the 
skin. 

41 . Tell about the growth of the hair. Its coarseness. How do 
we know that the hair lasts for a long time? 

42. When only will a nail grow? How can you determine the 
time required for nails to grow out? 

43. What is proud flesh? Where is it usually found? 

44. What causes proud flesh? Give a mode of treatment. 

7 


98 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


45. Of what are the warts an unnatural growth? 

46. How would you get rid of warts? 

47. Give the cause of corns. Tell how to get rid of them. 

48. What is an ingrowing toe-nail? 

49. Explain a mode of treatment to cure the same. Why is this 
disorder dangerous? 

50. Is dandruff indicative of any danger? 

51. What causes the hair to fall out? 

52. What should be done in such cases? 

53. Define chilblains. How treat the same? 

54. What is eczema? Give a general remedy. 


THE SKIN, HAIR, AND NAILS 


99 


BLACKBOARD OUTLINE. 

THE SKIN, HAIR, AND NAILS. 

1. Introduction. 

a. Uses of Skin. 

b. Definition. 

2. Strneture of the Skin. 

a. Epidermis — Cuticle or Scarf-Skin. 

b. Dermis — Cutis Vera, True Skin. 

c. Experiment, Growth, and Thickness. 

d. Glands— / > Their Functions. 

( Sweat, J 

{ Uses. 

Structure. 

Functions. 


3. Hair and Nails. 

a. Definition of Each. 

b. Uses of Each. 

c. Parts of Each. 


4. Functions and Hygiene of Skin, Hair, and Nails. 


a. Of the Skin. 

b. Of the Hair. 

c. Of the Nails. 


f Importance. 
Bathing — { How to Bathe. 

(When to Bathe. 


Clothing. 


5. Important Facts. 

1. Of the Skin. 

2. Of the Hair. 

3. Of the Nails. 


6 . Disorders of the Skin, Hair, and Nails, and their Treatment. 

a. Proud flesh. e. Dandruff. 

b. Warts. f. Chilblains. 

c. Corns. g. Eczema. 

d. Ingrowing Toe-Nail. 



V. 


THE CIRCULATION. 


Rnd red with Nature’s flame they start 
From the warm fountains of the heart, 

No rest that throbbing slave mag ask, 

Forever quivering o'er his task, 

Ufhile far and wide a crimson jet 
Leaps forth to fill the woven net 
U/hich in unnumbered crossing tides 
The flood of burning life divides, 

Then, kindling each decaying part, 

Creeps back to find the throbbing heart. — Holmes. 

( 101 ) 
















CIRCULATION OF THE BLOOD. 
(Heart, Lungs, Arteries and Veins.) 








V. The Circulation. 


1. THE BLOOD. 

Experiment. — Allow the blood of an animal 
to remain quiet in a vessel. In a few minutes it 
will coagulate, separating into two substances — a 
solid and a liquid. Stir the solid substance with a 
stick and you will see collected upon it many thread¬ 
like fibres. If the liquid part is boiled till the water 
in it escapes, the remaining substance will look like 
white jelly. 

The Composition of blood may be studied with 
much interest in view of this experiment. You will 
observe that the solid has a dark-red color, and is a 
sort of jelly. It is called the clot. The red color is 
due to the presence of minute bodies, which are 
held in suspension in the blood. Besides these red 
corpuscles , the clot contains a white, fibrinous mass, 
observed on the stick in the experiment — this is 
called animal fibrine . The liquid is called serum , 
which has a yellowish color; but if, by boiling it, 
we remove its water, it will coagulate to a white jelly, 
composed of albumen. These components of the 

(103) 


104 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


blood may be shown in the following form, or out¬ 
line :— 


Blood Corpuscles (red and white). 
Animal Fibrine. 



Blood. 


Water. 

Albumen. 


Serum. 


The red corpuscles of the human blood are cells 
of different sizes, having the form of discs, each of 
which has an area of nearly toVo of a square inch, 
and a thickness of about yoVo of an inch. They 
look somewhat like little pearl buttons without the 
holes in them, only they are red. They possess the 
remarkable property of adhering together in 
columns, like rolls of pennies; these rolls, more¬ 
over, join at their ends so as to cluster together, 
forming a sort of network (Fig. 21). 

Besides the red, there are white corpuscles in the 
blood. They differ from the former in their num¬ 
ber being much smaller than that of the red; for 
every five hundred red ones there exists, perhaps, 
one white corpuscle. During disease this ratio may 
increase to ten, and even more, for every five hun¬ 
dred. They are larger than the red corpuscles, and 
possess the peculiarity of alternately contracting 
and dilating, and otherwise changing their forms.* 

* The size and shape of the blood corpuscles vary in different 



THE CIRCULATION. 


105 


In Fig. 22, By there are four white; in A C> four 
red corpuscles, as seen through a microscope of 
very high magnifying power. 


B 



FIG. 21. 


fig. 22. 


The Use of these little bodies is not well deter¬ 
mined. The main purpose of the red seems to be 
to convey oxygen from the lungs to all parts of the 
body. It is observable also that they always con¬ 
tain iron. The white seem to be the agents of 
repair. This is thought to be true because when 
there is a wound or great inflammation in the body 
the number of this kind of corpuscles is known to 
increase. 

The Gases Contained in the blood are carbonic 
acid, oxygen, and a small quantity of nitrogen. 

animals, so that it is possible to discriminate "netween those of 
man and of the lower animals. 




106 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

One hundred volumes of blood contain about fifty 
volumes of these gases, collectively. 

The Specific Gravity of blood at a temperature 
of 60° F. is about the same as that of water. The 
temperature of the blood in the human body is 
generally 100° F. In the animal it has an odor 
faintly resembling that of the animal from which 
it came. 

The Quantity of blood in the living body is diffi¬ 
cult to ascertain; it has been estimated at about 
one-tenth of the weight of the entire body. In a 
thousand parts of weight of blood seven hundred 
and eighty-four parts are water, one hundred and 
thirty parts are red corpuscles, and the remainder 
is composed of albumen, fibrine, fat, and other 
matters. The proper composition of the blood is 
one of the three most important items in the health 
of man. The ravages of cholera and of similar dis¬ 
eases seem to result from a decomposition of this 
life-giving liquid. It will be seen, further on, that 
the health of the blood depends largely upon our food 
and upon the air we breathe. 

The Uses of the Blood.— Every living organism 
of the higher sort, whether animal or vegetable, 
requires for the maintenance of life and activity, a 


THE CIRCULATION. 


107 


circulatory fluid, by which nutriment is distributed 
to all its parts. In plants, this fluid is the sap; in 
insects, it is a watery and colorless blood; in reptiles 
and fishes, it is red but cold blood; while in the 
nobler animals and man, it is red and warm blood. 

The blood is the most important, as it is the most 
abundant, fluid of the body ; and upon its presence, 
under certain definite conditions, life depends. On 
this account it is frequently, and very properly, 

termed 44 the vital fluid.” The importance of the 

blood, as essential to life, was recognized in the 

earliest writings. In the narration of the death of 
the murdered Abel, it is written, 44 the voice of his 
blood crieth from the ground.” In the Mosaic law, 
proclaimed over thirty centuries ago, the Israelites 
were forbidden to eat food that contained blood, for 
the reason that 44 the life of the flesh is in the 

blood.” With the exception of a few tissues, such 
as the hair, the nails, and the cornea of the eye, 
blood everywhere pervades the body, as may be 
proved by puncturing any part with a needle. 

Of the uses of the blood when in the healthy state, 
the following four may here find a place : — 

(1) It is a source of nutritive material, whence the 
different parts of the body constantly draw for their 
maintenance. 


108 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


(2) It keeps all parts of the body warm and 
moist. 

(3) It conveys oxygen to those of the tissues 
which need this element. 

(4) It collects refuse from all parts of the body, 
and conveys the substances to places whence they 
may be discharged.* 

2. THE ORGANS OF CIRCULATION. 

Experiment. — Cut open a fresh plant and observe 
its juice. Next open an insect for the same purpose; 
it contains a watery, almost colorless juice or blood. 

* “You feel quite sure that blood is red, do you not? Well, 
it is no more red than the water of a stream would be if you were 
to fill it with little red fishes. Suppose the fishes to be very, very 
small — as small as a grain of sand — and closely crowded to¬ 
gether through the whole depth of the stream, the water would 
look red, would it not? And this is the way in which the blood 
looks red: only observe one thing — a grain of sand is a moun¬ 
tain in comparison with the little red bodies that float in the 
blood, which we have likened to little fishes. If I were to tell you 
they measured about the 3200th part of an inch in diameter, you 
would not be much the wiser; but if I tell you that in]a single drop 
of blood, such as might hang on the point of a needle, there are a 
million of these bodies, you will perceive that they are both very 
minute and very numerous. Not that any one has ever counted 
them, as you may suppose, but this is as close an estimate as can 
be made in view of what is known of their minute size.”— Mac&s 
History of a Mouthful of Bread. 



THE CIRCULATION 


109 



Then cut open a fish; its blood is cold. Lastly, 
procure some red, warm blood of a recently killed 
bird, or quadruped. 


FIG. 23. 

HEART, WITH TRUNKS OF PRINCIPAL ARTERIES AND VEINS. 

A, right ventricle. J3, left ventricle. (7, right auricle. D , left 
auricle. E , aorta. F, pulmonary artery. G, branchio-cephalic 
trunk. H, carotid, right and left. I, I, subclavian arteries. K, 
superior vena cava. L, pulmonary veins. 

The preceding shows that organisms have a fluid 
circulating through the body. 


110 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Man and the higher order of animals alone pos¬ 
sess warm blood. The “ vital fluid ” has a definite 
order in which it travels through the animal sys¬ 
tem. The circulation in the human body is the same 
as in mammals and birds. 

An uninterrupted current of blood through the 
body must be maintained. This is evident from the 
uses of the blood enumerated in the preceding 
pages. The question now arises, How does nature 
obtain such an unceasing stream rushing through 

O O Q 

countless tubes and channels? 

The Circulatory Organs through which this is ob¬ 
tained are the Hearty Arteries , Capillaries , and Veins. 

The Heart (Fig. 23), (represented also by 1, 
2, 3, 4, in Fig. 24) is a hollow muscle of about 
the size of its owner’s fist. This muscle has 
involuntary action, consisting of alternate con¬ 
traction and dilatation, which goes on without 
interruption until death.* Owing to the con- 

* The heart: “ You all know where it is. It is the most won¬ 
derful little pump in the world. There is no steam-engine half 
so clever at its work, or so strong. There it is, in every one of 
us, beat, beating —all day and all night, year after year, never 
stopping, like a watch ticking; only it never needs to be wound 
up,—God winds it up once for all.”— Author of “ Bob and His 
Friends .” 



THE CIRCULATION. 


Ill 


traction, the blood is 
expelled from the heart 
through arteries, and 
owing to the dilatation, 
it returns to the heart 
through veins. 

The Heart is Divided 
by a partition into two 
sides, right and left 
(Figs. 24, 25). These 
two sides do not com¬ 
municate with each 
other. Each of them 
has been subdivided 
into two portions, an 
upper and a lower, or 
into the auricle (1 or 
2) and ventricle (3 or 
4) respectively. The 
heart, therefore, con¬ 
tains two auricles (1, 
2) and two ventricles 
(3, 4). While the two 
divisions, right and left, 
are entirely separate 
from each other, each 



A DIAGRAM OF THE CIRCULATION. 
V 1 1^' Venous Blood. 


i _ Arterial Blood. 

Capillaries. 

Viewed from behind, so that the position 
of the observer corresponds with that of 
the figure. 











112 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


auricle communicates with the ventricle of the same 
side. The opening, however, through which the 
communication takes place, is so constructed that 
it acts like a valve, it allows the blood to pass 
from the auricle to the ventricle, but not in the 
opposite direction. 


The Course of the 
Blood from auricle to 
ventricle is in the same 
direction on each side. 





| The blood in the right 


§ auricle, Fig. 25 (2), is 

urged into the right 

ventricle (4), whence it 
passes through a large 

sels. altery 0 **) into the 

capillaries of the lungs. 


FIG. 25. 

The Heart and Large Blood Vessels, 


where it absorbs oxygen, and gives out carbonic 
acid. This artery is the pulmonary artery , one of 
the few arteries carrying venous blood, and called 
an artery simply on account of it being constructed 
like the arteries. The blood is then gathered up 
again and conveyed in large veins (pv) to the left 
auricle. This vein is called the pulmonary vein and 
is the only vein carrying arterial blood. The large 
vein by which the blood is poured back into the heart 



THE CIRCULATION. 


113 


is the vena cava. From the left auricle it emerges 
into the left ventricle (3), the strongest of the four 
divisions, and thence into the aorta , a, the strongest 
of the arteries. The aorta distributes it all over 
the system, to the capillaries of every portion of 
the body. In these capillaries the blood becomes 
impure, and after leaving them it passes through the 
large veins ( vc ) back into the right auricle (2), 
whence we supposed it to start. 

As stated before, the chief propelling force of the 
incessant torrent of blood through the body lies in 
the muscular substance of the heart. But there are 
several helpers which must not be disregarded: (1), 
the elastic walls of the arteries (they are not un¬ 
yielding like gas pipes); (2), the pressure of mus¬ 
cles upon some of the veins; and (3), the contrac¬ 
tion and expansion of the chest in breathing. These 
aids will be better understood hereafter. 

The Function of each Subdivision of the Heart 
may be stated thus :— 

a. The right auricle receives the venous blood of 
the whole body and conveys it to the right ventricle. 

b. The right ventricle impels the venous blood 
through an artery into the lungs. 

c. The left auricle receives arterial blood flowing to 
it through veins from the lungs. 

3 


114 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

d. The left ventricle forces the blood into the 
aorta, which distributes it over all parts of the body. 

In Comparing the functions of these subdivisions 
with one another it is found that — 

I. The auricles receive blood ; 

The left auricle receives arterial blood from the 
lungs; 

The right auricle, venous blood from the entire 
body. 

II. The ventricles convey away blood; 

The left ventricle conveys away arterial blood to 
the entire body ; 

The right ventricle, venous blood to the lungs. 

The Arteries are the cylindrical tubes that con¬ 
vey the blood from the heart to every part of the 
system. They are dense in structure, and preserve, 
for the most part, the cylindrical form, when 
emptied of their blood, which is their condition 
after death. 

The arteries are composed of three coats. The 
external, or cellular coat, is firm and strong; the 
middle, or fibrous coat, is composed of yellowish 
fibres. This coat is elastic, fragile, and thicker 


THE CIRCULATION. 


115 


than the external coat. Its elasticity enables the 
vessel to accommodate itself to the quantity of 
blood it may contain. The internal coat is a thin, 
serous membrane, which lines the interior of the 
artery, and gives it the smooth polish which that 
surface presents. It is continuous with the lining 
membrane of the heart. 

Communications between arteries are free and 
numerous. They increase in frequency with diminu¬ 
tion in the size of the branches, so that through the 
medium of the minute ramifications, the entire body 
may be considered as one circle of inosculation. 
The arteries, in their distribution through the body, 
are inclosed in a loose, cellular investment, called a 
sheath, which separates them from the surrounding 
tissues. 

The Pulmonary Artery (Fig. 25 ,pct) commences in 
front of the origin of the aorta. It ascends obliquely 
to the under surface of the arch of the aorta, where 
it divides into two branches, one of which passes 
to the right, the other to the left lung. These 
divide and subdivide in the structure of the lungs, 
and terminate in the capillary vessels, which form a 
network round the air-cells, and become continu¬ 
ous with the minute branches of the pulmonary 
veins. This artery conveys the impure blood to the 


116 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

lungs, and, with its corresponding veins, establishes 
the lesser , or pulmonic circulation. 

The Aorta proceeds from the left ventricle of the 
heart, and contains the pure, or nutrient blood. This 
trunk gives off branches, which divide and subdivide 
to their ultimate ramifications, constituting the great 
arterial tree which pervades, by its minute subdi¬ 
visions, every part of the animal frame. This great 
artery and its divisions, with their returning veins, 
constitute the greater , or systemic circulation . 

The Veins carry blood to the auricles of the heart, 
after it has been circulated by the arteries and cap¬ 
illaries through the tissues of the body. They are 
thinner and more delicate in structure than the arte¬ 
ries, so that when emptied of their blood, they be¬ 
come flattened and collapsed. The veins commence 
by minute radicles in the capillaries, which are every¬ 
where distributed through the textures of the body, 
and coalesce to constitute larger and larger branches, 
till they terminate in the large trunks which convey 
the dark-colored blood directly to the heart. In 
diameter they are much larger than the arteries, and, 
like those vessels, their combined area would consti¬ 
tute an imaginary cone, the apex of which is placed 
at the heart, and the base at the surface of the 
body. 


THE CIRCULATION. 


117 


The communications between the veins are more 
frequent than between the arteries, ami take place 
between the larger as well as among the smaller 
vessels. The office of these inosculations is very ap¬ 
parent, as tending to obviate the obstructions to 
which the veins are peculiarly liable, from the thin¬ 
ness of their coats, and from inability to overcome 
great impediments by the force of their current. 
These tubes, as well as the arteries, are supplied with 
nutrient vessels, and it is to be presumed that nerv¬ 
ous filaments from the sympathetic nerves are dis¬ 
tributed to their coats. 

The external, or cellular coat of the veins, is dense 
and firm, resembling the cellular tunic of the arteries. 
The middle coat is fibrous, like that of the arteries, 
but extremely thin. The internal coat is serous, and 
also similar to that of the arteries. It is continuous 
with the lining membrane of the heart at one 
extremity, and with the lining membrane of the 
capillaries at the other. 

At certain intervals the internal coat forms folds, 
which are called valves (Fig. 26). They are for the 
most part composed of two folds, semi-lunar in 
shape, one on each side of the inner wall of the vein. 
The free edge of the fold is concave and extends for¬ 
ward in the direction the blood should go, so while 
the current of blood sets forward towards the heart 


118 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


there is no hindrance to the free passage; but if the 
current is retrograde, it is impeded by their disten¬ 
sion. These 
v a 1 v es are 
most numer¬ 
ous in the 
e xtremities; 
but in some 
of the trunk 
veins, and 
even in some 
small veins, 
there are no 
valves. 

The Capillaries (Fig. 27) constitute a microscopic 
network, and are so distributed through every part of 
the body as to render it impossible to introduce the 
smallest needle beneath the skin, without wounding 
several of these fine vessels. They are remarkable 
for the uniformity of diameter, and for the constant 
divisions and communications which take place be¬ 
tween them. 

The capillaries inosculate, on the one hand, with 
the terminal extremity of the arteries, and on the 
other, with the commencement of the veins. They 
establish the communication between the termination 





THE CIRCULATION. 


119 


of the arteries and 
the beginning of the 
veins. The impor¬ 
tant operations of 
secretion and the 
conversion of the 
nutrient materials of 
the blood into bone, 
muscle, etc., are 
performed in these 
vessels. 



3. THE CIRCULATION OF THE BLOOD. 

Experiment.— Examine the movements of the 
heart by placing the fingers between the fifth and 
sixth ribs, slightly to the left of the breast-bone (as 
the lower part of the heart inclines a little toward the 
left). Each contraction of the heart will then be 
distinctly felt, because the point of the heart strikes 
against the wall of the chest. 

The heart of a living animal, if quickly removed, 
will continue pulsating for some time. Each pulsa¬ 
tion commences at the two auricles, and thence 
passes to the two ventricles. That is to say, each 
pulsation of the heart consists of—(1), a simultane¬ 
ous contraction of both auricles; (2), immediately 


120 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

after this a simultaneous contraction of both ventri¬ 
cles; (3), a moment of rest or relaxation. 

After this rest the contractions commence again in 
the same order as before, and the relaxations occur 
also in the same order as before. The work of the 
heart is carried on, as all labor should be, regularly 
and continuously, with due regard to rest. 

The Two Contractions of the heart with its subse¬ 
quent repose, are often represented by two short 
marks and a rest thus; w w —. The contraction 
of either auricle or ventricle is called its systole; 
the pause during the dilatation of either auricle or 
ventricle is called the diastole. This diastole, or 
pause, occupies about the same length of time as 
the two systoles together; so the heart’s action has a 
certain rhythm. 

The Action of the Heart may now be explained. 
It is filled with blood, and the first contraction, or 
the systole of the auricles, happens. The auricles 
are, as it were, pressed together, and the liquid 
within is forced out. Where can it go? On exam¬ 
ining Fig. 24, two outlets are found to exist. It 
may pass back into the veins, or else descend into the 
ventricles. The amount of resistance encountered 
in each direction will decide the question. The re- 


the circulation. 


121 


sistanee encountered toward the veins is very great, 
because exerted by the blood in all the veins; that 
encountered toward the ventricles will be exceed¬ 
ingly small, because, in the first place, the valves 
leading into the ventricles are open ; in the second 
place, the walls of the ventricles, in their relaxed 
state, are easily expanded ; and in the third place, the 
resisting pressure of the arterial blood is rendered 
naught by the valves between the ventricles and 
arteries being closed. For these reasons only very 
little blood will pass back to the veins; nearly all of 
it rushes at once into the ventricles. When the 
ventricles are thus filling they become expanded, 
and the blood getting behind the valves which 
separate each auricle from its ventricle, the ven¬ 
tricles are soon closed. The contraction of the 
auricles now ceases, their walls relax and immedi¬ 
ately blood from the veins enters them, slowly ex¬ 
panding them again. The auricular systole is now 
over. 

The next movement of the heart is the contraction 
of both ventricles. The walls of the ventricles are 
strong and thick; the pressure, therefore, which 
they produce in suddenly contracting is very great, 
and has the effect of shutting up the auriculo-ven- 
tricular valves so that not a drop of blood can enter 
the auricles. But it is towards the arteries that the 


122 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

ventricles meet with most of the resistance. There 
is the resisting pressure of the blood in the arteries, 
a pressure which is very great because it is made 
up— first , of the weight of the blood; second , of 
the resistance of the walls of the arteries to further 
expansion; third , of the friction of the blood in the 
capillaries. All this explains why the walls of the 
ventricles are built so very strong: they have more 
work to perform than the auricles. It also shows 
the necessity of the valves between the auricles and 
ventricles, and that no valves are needed between 
the auricles and veins. The auriculo-ventricular 
valves act like the lower valve in a pump. The 
whole office of the auricles seems to be to fill the 
ventricles. And the contraction of the left ven¬ 
tricle forces the blood into the arterial system of 
the body, while the contraction of the right ventricle 
impels the blood into the artery of the lungs. This 
simultaneous contraction of the ventricles forms the 
ventricular systole. 

The Arteries Receive a fresh supply of blood at 
every systole of the ventricles; during a part of the 
time in which they transmit the shock, the diastole 
of the heart occurs. Each ventricle contains about 
three ounces of blood; the whole of this passes, at 
each contraction, into the respective arteries. The 


THE CIRCULATION. 


123 


great pressure of this quantit}' of blood (about one- 
fifth of the pressure of the atmosphere) suddenly 
forced into the main arteries, necessarily distends 
them, because they are elastic and yielding ; but a 
reaction takes place, and the elastic walls of the 
arteries contract again. This contraction has two 
effects in opposite directions: it causes, first , the 
valves between the arteries and ventricles to close 
instantly; second , the blood to pass from the larger 
to the smaller arteries. Thence the fluid enters the 
ramification of the capillaries (Fig. 27). A little 
reflection will show that a corresponding quantity of 
blood passes at the same time from the capillaries 
through the veins back toward the heart. The 
effect , then, of the ventricular systole is — (1), the 
propulsion of blood through the arteries into the 
capillaries; and (2), the return of the fluid from the 
capillaries through the veins to the heart. 

The impulse given at every ventricular systole to 
the blood in the aorta is spent in urging the blood* 
forward through the arteries; and, next, in distend¬ 
ing the elastic walls of the arteries. This sudden 
expansion produces a sudden recoil, and gives rise 
to a phenomenon, which is called the pulse. The 
pulse proper is the expansion of the artery, felt on 
examining the artery. Each pulsation naturally 
means a systole of the ventricles. Such pulsations 


124 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

may be felt wherever arteries are exposed to the 
touch, as on each upper side of the neck, in front of 
the ear, or above the wrist. At the wrist the pulse 
is felt to be a little later than at the heart or middle 
of the neck. It occurs later, according to the dis¬ 
tance from the heart at which the artery is examined. 
To feel the pulse, the wrist is selected by physicians 
for convenience sake. The pulse is the index of the 
motions of the heart. Its regularit}', strength, full¬ 
ness, and a number of peculiarities, indicate the state 
of affairs respecting the heart and its fluid. 

The Sounds of the Heart may be distinctl} r heard 
by placing the ear closely over the heart. They 
should occur with great regularity — first, a pro¬ 
longed, dull sound, somewhat like that of the word 
lubb; then a short and sharp sound; nearly like 
that of dup; then comes a pause; then the long 
sound again, and then the short sound; then the 
pause, the long sound, and so on. The sharp, short 
sound comes from the sudden closing of the valves 
between the ventricles and the arteries ; the cause of 
the long sound is not fully known, as yet. 

The capillaries are pulseless, because on reaching 
them the shock is spread over a large network of 
capillary tubes; this makes its effect imperceptible. 
For the same reason, the blood in the capillaries 


THE CIRCULATION. 


125 


flows steadily, while from a severed artery it jets 
forth in jerks. The elasticity of the arteries seems 
to do for the blood what an air chamber does for 
the water of a pump. 

From what has been said in regard to the arteries, 
their uses chiefly are — first , to convey blood to the 
system, and secondly , to convert the jerking motion 
of the blood into a uniform flow. 

Experiment.— Clasp the lower part of the arm 
tightly a little above the wrist; the veins on the 
back of the hand will soon distend, and knotty points 
become visible. When the pressure is removed they 
will empty themselves, and the swelling disappears. 
Now, why did this not completely check the cir¬ 
culation of the blood? There are two reasons: In 
the first place, the veins communicate with each 
other by means of many branches, so that whenever 
the blood, for any reason, be stopped in one vein, 
it at once passes through branch vessels to another, 
unimpeded vein, and finally to the heart. But it 
may be argued that in the above experiment the 
arm had been encircled with so much pressure that 
even the branch vessels were closed. Circulation, 
would, nevertheless, have continued, because, in the 
second place, the veins are provided with valves 
(Fig. 2G) which are open as long as the fluid flows 


126 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


toward the heart, but which close when it moves in 
the opposite direction. Those knotty places were 
the closed valves, preventing the backward flow of 
the blood to the capillaries.* Were it not for this 
valvular action in the veins, any such disturbance 
as the one occasioned by the experiment, would 
impel the blood to the capillaries, where it would 
resist, and Anally overcome, the onward motion of 


* Course of the Blood in the Capillaries.— (i The phenomena of 
the capillary circulation are only observable with the aid of the 
microscope. It was not granted to the discoverer of the circula¬ 
tion to see the blood moving through the capillaries, and he 
never knew the exact mode of communication between the 
arteries and veins. After it was pretty generally acknowledged 
that the blood did pass from the arteries to the veins, it was 
disputed whether it passed in an intermediate system of ves¬ 
sels, or became diffused in the substance of the tissues, like a 
river flowing between numberless little islands, to be collected 
by the venous radicles and conveyed to the heart. Accurate 
microscopic investigations have now demonstrated the exist¬ 
ence, and given us a clear idea of the anatomy of the inter¬ 
mediate vessels. In 1661 the celebrated anatomist Malpighi first 
saw the movement of the blood in the capillaries, in the lungs 
of a frog. This spectacle has ever since been the delight of 
the physiologist. We see the great arterial rivers, in which the 
blood flows with wonderful rapidity, branching and subdividing, 
until the blood is brought to the superb network of fine capil¬ 
laries, where the corpuscles dart along one by one, the fluid 
then being collected by the veins and carried in great currents 
to the heart.”— Flint. 



THE CIRCULATION. 


127 


the blood in the arteries, which would speedily in¬ 
terrupt the circulation. 

The Frequency of pulsations depends upon the 
age, sex, and health of a person. During the first 
years of life about 130 pulse-beats may be counted 
in a minute, while twenty years later the same per¬ 
son’s pulse will beat nearly 70 times, and increase 
again toward old age. The pulse of women beats 
more rapidly than that of men. 


4. THE LYMPHATIC CIRCULATION. 

Closely associated with that of the blood is the 
Lymphatic Circulation . This is far more delicate in 
its organization, however, and is not so fully under¬ 
stood. It reaches almost every part of the body in a 
second series of capillaries interlaced with the blood- 
capillaries whose function seems to be the removal of 
matter which has been deposited. 

In Structure these vessels resemble the lacteals 
mentioned under the subject of digestion. 

They exist in great numbers in the skin and 
mucous membranes, particularly those of the 
lungs. Though no lymphatics have been traced 
to the brain, it is presumed that they exist 


128 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

there, as this part of the body is not exempt from 
the composition and decomposition, which are 

perpetual in the body. 
These vessels are ex¬ 
tremely minute at their 
origin, so that in many 
parts of the system 
they cannot be detected 
without the aid of a 
microscope. 

The lymphatic vessels, 
like the veins, diminish 
in number as they in¬ 
crease in size, while pur¬ 
suing their course toward 
the large veins near the 
heart, into which they 

b. The valves of a lymphatic p 0ur their contents. 

trunk ' The walls of these ves- 

c. 1 . A lymphatic gland with 

several vessels passing through it. se ^ s have two coats ol 

which the external one is 
cellular, and is capable of considerable distention. 
The internal coat is folded so as to form valves like 
those in the veins. Their walls are so thin, that these 
folds gives them the appearance of being knotted. 

At certain points, the lymphatic vessels pass 
through distinct, soft bodies, peculiar to themselves, 



FIG. 28 . 

a. A single lymphatic vessel, 
much magnified. 


THE CIRCULATION. 


129 


which are called lymphatic glands , which are to these 
vessels what the mesenteric glands are to the lacteals. 
The lymphatic glands vary in form and in size. 
They are extremely vascular, and appear to consist of 



FIG. 29. 


Lymphatics of the Head and Neck, showing the Glands, and B t 
the thoracic duct as it empties into the left innominate vein at the 
junction of the left jugular and subclavian veins. 

a collection of minute vessels. These glands are 
found in different parts of the body, but are most 
numerous in the groins, axilla, or arm-pits, neck, and 
cavities of the chest and abdomen.* 


* From exposure to cold, these glands are frequently enlarged 
and inflamed. They are then known under the name of “ kernels.” 
They are often diseased, particularly in scrofula, or “king’s evil. ,, 

9 



130 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

The Lymph, which circulates through the lym¬ 
phatic system, is a thin, colorless liquid similar to the 
serum of the blood. It is gathered up by the 
lymphatics and after undergoing some change in the 
glands not well known, is poured into the blood 
through the thoracic duct into the vena cava in the 
neck. The lymphatics perform the office of absorp¬ 
tion chiefly in the skin.* When a wound, a cut or 
the like, is to be healed an excess of matter is 
deposited in the sore. Soon these vessels remove 
the surplus material to other parts of the body. 


5. HYGIENE AND DISORDERS OF THE 
CIRCULATORY SYSTEM. 

The Vitality and Vigor of every part of the 
human body depend upon the condition of the blood 
and its circulation. The conditions which will favor 
this requirement may be stated in the following 
rules: — 

(1) The Clothing should he Loosely Worn .— Com¬ 
pression of any kind, impedes the passage of blood 
through the vessels of the compressed portion. 

* Pain is often relieved by injecting under the skin a solution 
of morphine. The lymphatics take up the drug and carry it 
through the system. 



THE CIRCULATION. 


131 


Hence, no article of apparel should be worn so as 
to prevent a free flow of blood through every organ 
of the body. 

The blood which passes to and from the brain 
flows through the vessels of the neck. If the dress¬ 
ing of this part of the body is close, the circulation 
will be impeded, and the functions of the brain will 
be impaired. This remark is particularly important 
to scholars, public speakers, and individuals predis¬ 
posed to apoplexy, and other diseases of the brain. 

As many of the large veins through which the 
blood is returned from the lower extremities, lie im¬ 
mediately beneath the skin, if the ligatures used to 
retain the hose, or any other article of apparel, in 
proper position, be tight and inelastic, the passage 
of blood through these vessels will be obstructed, 
producing, by their distention, the varicose or 
enlarged veins. Hence elastic bands should always 
be used for these purposes. 

(2) An Equal Temperature of All Parts of the 
System Promotes Health A chill on one portion 
of the body diminishes the size of its circulating 
vessels, and the blood which should distend and 
stimulate the chilled part, will accumulate in other 
organs. The deficiency of blood in the chilled por¬ 
tion induces weakness, while the superabundance 


132 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

of sanguineous fluid may cause disease in another 
part of the system. 

(3) The Skin should be kept not only of an Equal 
but at its Natural Temperature .— If the skin is not 
kept warm by adequate clothing, so that chills 
produce a contraction of the blood-vessels and 
a consequent paleness, the blood will recede from 
the surface of the body, and accumulate in the in¬ 
ternal organs. Cleanliness of the skin is likewise 
necessary, for the reason that this condition favors 
the free action of the cutaneous vessels. 

When intending to ride on a cold day, wash the 
face, hands, and feet, in cold water, and rub them 
smartly with a coarse towel. This is far better to 
keep the extremities warm than to take spirits into 
the stomach. 

(4) Exercise Promotes the Circulation of the 
Blood .— As the action of the muscles is one of the 
important agents which propel the blood through 
the arteries and veins, daily and regular exercise of 
the muscular system is required to sustain a vigor¬ 
ous circulation in the extremities and skin, and also 
to maintain a healthy condition of the system. 

(5) The State of the Mind has Great Influence 
Upon the Circulation .— Let there be hope and joy 


THE CIRCULATION. 


133 


and the system is more fully nourished and capable of 
greater extension, than when despair and sorrow 
prevail. 

(6) The Blood Should he Pure and Abundant .— 
In consequence the organs will act more energeti¬ 
cally. 

(7) Absorption into the Lymphatics is Greatest 
When There is Some Break in the Cuticle .— 
Through the lymphatic capillaries poison may be 
communicated to the blood from the surface of the 
body. Great care should be exercised as to the 
cleanliness of a cut or other wound to avoid such a 
thing. Very serious cases of blood-poisoning have 
occurred by neglecting this precaution. 

Diseases of this system are so common that a few 
remarks concerning them may not be out of place in 
this connection. 

(1) Congestion , as the term indicates, is an undue 
accumulation of blood in any particular part of the 
body. This is known by redness of the part beyond 
the normal appearance. This may become a perma¬ 
nent condition as in the case of the man addicted to 
drink when his nose becomes red. The vital organs 


134 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

may become gorged with blood, producing very 
serious results. Blushing is a temporary congestion, 
due to nervous excitement which causes an expansion 
of the capillaries for an instant, thus allowing an 
unusual amount of blood in that part, usually the 
face. 

(2) Inflammation , simply a burning, is a more or 
less permanent congestion of some part of the body. 
There are four characteristics of this disorder — red¬ 
ness , heat, pain, swelling. Catarrhal affections are 
inflammations of the mucous linings of the various 
passages in the body. The most common of these 
troubles are those of the nasal and bronchial tubes. 
On going out from the hot, dry air of a warm room, 
into a cold, damp atmosphere, it is almost impossible 
to avoid irritation and inflammation of this tender 
membrane. If our rooms were heated less intensely 
and ventilated more thoroughly this disease of catarrh 
would be far less common. 

(3) Scrofula is a blood trouble which is inherited. 
It affects the glands of the lymphatic system. Yet it 
may attack any organ. To ward off approaches of 
this disease it is necessary to use the utmost care in 
diet and exercise ; to look well to pure air and warm 
clothing, avoiding late hours and undue use of stimu- 


THE CIRCULATION. 


135 


lants. Impure air and insufficient food are the 
greatest causes of scrofulous attacks. 

(4) A cold is caused by the skin being chilled and 
the perspiration stopped. The effect is that the blood 
is not purified as it should be by the proper action of 
the pores of the skin. The lungs are consequently 
burdened with extra work and the membranes of the 
lungs and bronchial tubes are irritated. This irrita¬ 
tion amounts in short to congestion and then inflam¬ 
mation. In general it may be taken as a truth that 
the excess of blood will seek the weak part and there 
develop latent disease. When this congestion locates 
in the membranes of the nasal cavities we have “a 
cold in the head,” or a catarrh . By a hot foot-bath 
the equipoise is partially restored by gorging the feet 
with blood, thus relieving the congested part. No 
other one thing is so efficacious in the treatment 
of a cold as a hot foot-bath. It has saved many 
lives. 

Yet it should not be thought that a “ cold ” is the 
great cause of diseases. In this connection we quote 
from an eminent authority :— 

“ A reform is greatly needed in respect to 4 catching 
cold.’ Few diseases are referable to the agency of 
cold, and even the affectation commonly called a cold 
is generally caused by other agencies, or, perhaps, by 


136 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

a special agent, which may prove to be a microbe. 
Let the axiom, ‘ A fever 'patient never catches cold ,’ 
be reiterated until it becomes a household phrase. 
Let the restorative influence of cool, fresh, pure 
atmosphere be inculcated. Let it be understood that 
in therapeutics, as in hygiene, the single word comfort 
embodies the principles which should regulate cover¬ 
ings and clothing.”— Austin Flint , M. D., in the 
Few York Medical Journal . 

(5). The Heart is Injured by Overexertion .— 
“ During exertion, if the heart is not oppressed, its 
movements, though rapid and forcible, are regular 
and equal. But when it becomes embarrassed, the 
pulse-beats are quick, unequal, and at last become 
irregular, indicating injury to the organ. All great 
and sudden efforts are to be carefully avoided; 
excessive exercise often produces palpitation, and 
sometimes enlargement and valvular diseases of the 
heart.’ ’ — Huxley . 

“ No great intellectual thing was ever done by great 
effort; a great thing can only be done by a great man, 
and he does it without effort. The body’s work and 
tbc head’s work are to be done quietly, and compara¬ 
tively without effort. Neither limbs nor brain are ever 
to be strained to their utmost; that is not the way in 


THE CIRCULATION. 


137 


which the greatest quantity of work is to be got out 
of them ; they are never to be worked furiously, but 
with tranquillity and constancy. We are to follow the 
plow from sunrise to sunset, but not to pull in race- 
boats at the twilight; we shall get no fruit of 
that kind of work—only disease of the heart.”— 
Buskin. 

Important Facts. — The hearts of all Mammals 
have two auricles and two ventricles. In quadrupeds 
the heart lies on the middle line of the body, and not 
to the left of it as in man. The blood of birds has 
the highest temperature of the vertebrate animals. 
In all reptiles the heart has two auricles and one ven¬ 
tricle; and their blood is cold. The heart of the fish 
has one auricle and one ventricle. In the crab and 
the lobster the heart consists of a single ventricle. 
Insects have neither arteries nor veins. Coagulation 
of the blood, which is of so much value as a means of 
stopping hemorrhages, is greater in the lower animals, 
in some species of birds almost instantaneous. This 
seems to be a wise provision since these animals can¬ 
not stop a flow of blood from a wound by artificial 
means. The office of fibrine is thought to be to stanch 
hemorrhage. The blood of man carries a great 
amount of iron. Enough has been found in the 
ashes of a burned body to make a ring the size 


138 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

of an ordinary finger-ring. The fact that the 
arteries and veins in all parts of the body 
are connected by cross branches, makes it pos¬ 
sible to amputate a limb and yet leave the circula¬ 
tory system intact. A deep breath helps the flow of 
blood in the veins and a cut, or wound, may suck in 
air with fatal effect. A maimed horse is most mer¬ 
cifully killed by blowing a bubble of air into the 
veins of his neck. A whale has no valve in his veins 
because the pressure of the sea would burst them ; 
hence a small wound by a harpoon causes him to 
bleed to death. The circulation of the blood was 
discovered by Harvey in 1619. He kept it a secret 
for a long time. When he at length published it he 
was bitterly persecuted. He lived, however, to see 
his theory universally accepted. Our bodies change 
entirely every few years — some say the period is 
seven years; this must vary according to the manner 
of life. The amount of work performed by some 
organs of the body is truly wonderful. The heart 
beats forty million times per year. Dr. Holmes has 
said that our brains are seventy-five-year clocks. It 
may be interesting here to take a comparative view 
of the heart-beats in different animals shown by a 
table compiled from experiments made in Paris. The 
pulse of a lion beats forty times a minute; that of a 
tiger, ninety-six times ; of a tapir, forty-four times ; of 


THE CIRCULATION. 


139 


of a horse, forty times; of a wolf, forty-five times; of 
a fox, forty-three times; of a bear, thirty-eight times; 
of a monkey, forty-eight times; of an eagle, one 
hundred and sixty times. It was impossible to deter¬ 
mine the beatings of the elephant’s pulse. A butter¬ 
fly, however, it was discovered, experienced sixty 
heart pulsations in a minute. 


140 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


REVIEW QUESTIONS. 

1. Give an experiment by which the composition of the blood 
may be shown. 

2. What is the composition of the blood? 

3. Describe the corpuscles of the human blood? 

4. What is said of their use? 

5. What gases are contained in the blood? 

6. What can you say of the quantity of blood in the body? 

7. Why is the blood called “the vital fluid?” 

8. What ancient reference to blood can you give? 

9. State the four chief uses of the blood? 

10. Why should there be organs for circulation? 

11. Name these organs. 

12. Describe the heart. 

13. Locate the auricles. 

14. Locate the ventricles. 

15. What are the vessels leading from the heart? 

16. What are the vessels leading to the heart? 

17. Why is the left side of the heart the stronger? 

18. Why is the aorta the strongest of the arteries? 

19. State the function of each subdivision of the heart. 

20. Compare the auricles and the ventricles as to work. 

21. Describe the arteries. 

22. What is the work of the pulmonary artery? 

23. What organs in the pulmonic circulation? 

24. What organs in the systemic circulation? 

25. Describe the veins. 

26. What are the valves of the veins? 

27. What are the capillaries? 


THE BLOOD. 


141 


28. Locate them. 

29. Describe the actions of the heart. 

30. Trace the circulation. 

31. How may we show the location of the valves in veins? 

82. What can you say of the frequency of the pulse-beats? 

33. Describe the lymphatic circulation. 

34. What are its uses? 

35. Where are they most numerous? 

36. Into what organ do they empty their contents? 

37. What are the lymphatic glands? 

38. Where are they? 

39. What is the lymph? 

40. How may pain be relieved? 

41. Upon what does the vitality and vigor of the body depend? 

42. State the law of hygiene for the clothing. 

43. Discuss the rule of equal temperature. 

44. What does exercise have to do with the circulation? 

45. The state of the mind? 

46. What care should b3 exercised as to absorption? 

47. Describe congestion. 

48. What is blushing? 

49. What are the signs of inflammation? 

50. What is a cold and what some of its consequences? 

51. What is a good treatment for a cold? Why? 

52. State five important facts. 

53. Who discovered the circulation of the blood? 


142 


ANATOMY, PHYSIOLOGY, AND HYGIENE 


BLACKBOARD OUTLINE. 

THE CIRCULATORY SYSTEM. 


1. The Blood. 

1. Composition. 

2. Uses. 

3. Coagulation. 

4. Quality. 

2. The Organs of Circulation. 

1. The Heart. 

Divisions and Walls. 
Valves. 

Movements. 

2. The Arteries. 

Structure and Character 
Main Branches. 

The Pulse. 

3. The Capillaries. 

Description. 

4. The Veins. 

Structure. 

Valves, 

3. The Clrcnlation. 

1. The Pulmonic Circulation 

2. The Systemic Circulation. 

3. The Lymphatic Circulation. 

Description. 

The Glands. 

The Lymph. 

4. Hygiene and Disorders. 

1. Laws of Health. 

2. Diseases. 

Congestion. 

Inilammation, 

Scrofula. 

Cold. 

Over-exertion. 


VI. 


THE RESPIRATORY SYSTEM AND 
VOICE. 


Look in upon thy wondrous frame! 

The smooth, soft air with pulse-like waves 
Flows murmuring through its hidden caves, 

Whose streams of brightening purple rush, 

Fired with a new and livelier blush, 

While all their burden of decay, 

The ebbing current steals away, 

— Holmes, " The Living Temple,'' 

( 143 ) 




VI. The Respiratory System and Voice. 


1. INTRODUCTION. 

Iii tlie Preceding Chapter the JBlood has been 
traced in its travels through the body, but now 
the discussion of how the blood reaches the air in 
the lungs and is there purified, again to begin its 
journey through the system, will be taken up, and 
the process fully explained. 

The first object in the process of respiration is 
to supply the system with oxygen, which is absolutely 
necessary to the life of tissues. Again, the process 
of respiration relieves the system of waste matter, 
chiefly carbon, with watery vapor. The gluten of 
vegetable food is also converted into jibrine through 
the influence of the air upon the blood. 

Wherever man sojourns, whether within doors or 
out, whether below, above, or at the surface of the 
earth, he requires, night and day, an incessant sup¬ 
ply of air, which he mainly uses for food, and as 
a means of cooling the body. 

(Our atmospheric air is a mixture of two gases — 
nitrogen and oxygen; only the latter is available 

(145) 


10 


146 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

for food; nitrogen is not utilized for any purpose 
by the blood. It merely dilutes the oxygen, which 
otherwise would be too strong. Oxygen forms one- 
fifth of any given volume of the atmosphere ; nitro¬ 
gen, the remaining four-fifths including a little 
watery vapor, carbonic acid gas.) 

The human body, in order properly to carry on 
the functions of life, requires a constant internal 
temperature, which, in summer and winter, must be 
the same. Experiments have shown this tempera¬ 
ture to be between 98° and 100° F. ; and, as it does 
not vary under ordinary circumstances, this vital or 
animal heat, as it is called, must be generated in, 
and distributed through, the interior of the body at 
every instant of time. In severe cold weather the 
temperature of the air may be so low that one’s 
ears or finger-ends may be cooled a few degrees 
below 98°, or even congeal; but the temperature of 
the interior organs and of the blood remains un¬ 
changed. Should the cold be very intense, however, 
and affect the body continuously, then the tempera¬ 
ture of the blood will be reduced, and the conse¬ 
quences be fatal. A decrease of five degrees below 
the normal standard of temperature will cause the 
vital processes to cease. 

A temperature not varying more than one degree 
from 99° F ., whatever he the temperature of the 


THE RESPIRATORY SYSTEM AND VOICE. 147 


surrounding air , is one of the three most important 
requirements for health. 

How the Heat of the Body May Be Maintained.— 
It is obvious that the maintenance of the standard 
temperature of the body must be one of our main 
cares. Heat may be lost—(1), By conduction; 
(2), By radiation; and (3), By evaporation. 

(l) Loss of Heat by Conduction — Experi¬ 
ment. — The end of a wire held in a flame has a 
higher temperature than its nearest part outside 
the flame, while the end of the wire which is 
held in the hand is comparatively cool. We say 
now that the wire is unequally hot; and because of 
this inequality of temperature, the heat commences 
to pass from the hotter to the colder portions of 
the wire, so that, finally, the hand can no longer 
hold it. 

In the same manner the human body transfers 
heat to any substance in contact with it and colder 
than itself, such as air, water, or clothing. 

The passage of heat from hotter to colder portions 
of a body, or from hotter to colder adjacent bodies, 
is called the conduction of heat. 

If, by way of experiment, wo were to step from a 
heated room suddenly into an apartment whose 


148 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

temperature was 32° F., a great deal of heat would 
be conducted away from the body, and the loss 
would at once be seriously felt; but were we, in a 
heated state, to plunge into ice-cold water, the loss 
of heat would be far greater—that is, the water 
would take more heat from the body than the air, 
and we should be chilled instantaneously. This 
shows that water is a better conductor of heat than 
air. It also explains why we take cold more easily 
in moist and cold weather, than in dry and cold. 

(2) Loss of Heat by Radiation — Familiar 
Facts.— On a bright, calm day in winter we feel 
the sun’s rays to be quite warm, although the 
water on the ground is freezing, and the ice is dry 
and hard. The thermometer indicates a temperature 
below the freezing point, but when the direct rays of 
the sun fall on it, it rises at once, indicating a far 
higher temperature. This shows that the sun’s rays 
pass through the air without heating it, but that they 
heat any object, such as a solid body, which stops 
them. 

This passage of heat-rays from one body to another 
without affecting the air through which they pass is 
called the radiation of heat. It differs from conduc¬ 
tion, inasmuch as the radiating body is not in contact 
with the body heated, while conduction means the 


THE RESPIRATORY SYSTEM AND VOICE. 149 


passage of heat from hotter to colder parts of the 
same substance, or of adjacent bodies. 

On a cold day, if a person is seated by a window in 
a warm room, his loss of heat by radiation is only 
partial, and, therefore, more dangerous than an equal 
radiation from all parts of his body, such as takes 
place when he is walking out of doors. A partial 
radiation may produce a cold, and, if continued, entail 
serious injuries upon the system. 

As the human body heats the air around it by con¬ 
duction, and as warm air has less specific weight than 
cold air, currents of warmed air continuously ascend 
along the body. These currents are interfered with 
by the atmosphere, which constantly penetrates to 
the body, becomes heated at its expense, and thus 
exerts a cooling influence upon it. Hence, we feel 
colder when windy weather sets in, although the ther¬ 
mometer shows no reduction of temperature. 

All bodies continually tend to equalize their temper¬ 
atures by the diffusion of heat . This diffusion of 
heat takes place by conduction and radiation. 

(3) Loss of Heat by Evaporation — Familiar 
Facts. — A few drops of alcohol or ether, placed 
upon the bulb of a thermometer, will rapidly 
evaporate; this causes an immediate reduction of 
temperature, which is indicated by the thermometer. 


150 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


So, snow and ice, when melting on the ground, 
reduce the temperature of the air. 

Now, evaporation means the conversion of a liquid 
into the gaseous state. The conversion of solids 
into the liquid or gaseous state is called melting 
or fusion. 

Whenever substances evaporate or melt , they ab¬ 
sorb heat; this heat is taken from the adjacent 
body , and this body is thereby chilled. 

In the case of the alcohol, the heat was given 
to it by the thermometer; in the case of snow 
and ice melting on the ground, the heat was com¬ 
municated by the air. Both, the thermometer and 
the air, under those circumstances suffered a loss 
of heat; this is the reason why the thermometer 
sank, and the air became chilled. 


2. THE ORGANS OF RESPIRATION AND 
VOICE—THEIR STRUCTURE. 

The blood nourishes the different parts of the 
body, and at the same time removes effete mat¬ 
ter — that is, all such particles as have served 
their functions in the body. This gives rise to 
two distinct kinds of blood, the arterial , or nu¬ 
trient, and the venous , the carrier of waste mat¬ 
ter. The most important difference between the 


THE RESPIRATORY SYSTEM AND VOICE. 


151 


two is, that venous blood contains less oxygen and 
more carbonic acid gas than the arterial. The latter 
is of a scarlet color, but in passing through the 
capillaries of the body it is converted into venous 
blood, at the same time becoming darker. The 
venous blood passes from the heart to the lungs, 
where it is converted into arterial blood b}^ the 
absorption of oxygen gas. This conversion is 
mainly effected by the peculiar structure of the 
lungs; it is aided by the acts of inspiration and 
expiration, as well as by other processes. The 
conversion takes place during the passage of 
venous blood through the capillaries of the lungs 
aided by the other organs of respiration (Fig. 30). 

The Organs of Respiration are: The Lungs , 

the Air-Passages, the Pleura , the Larynx , the 
Trachea , the Bronchi , and some Muscles , including 
the Diaphragm. 

The Lungs occupy the greater portion of the chest 
cavity; in fact, about four-fifths of it; they are sit¬ 
uated on both sides of the heart, and are of a pinkish 
gray color, and dotted with black spots (l H ig. 30). 
They receive air through the larynx and the trachea, 
which communicate with the external air by two 
channels — the mouth and the nasal tubes. The 



152 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


mouth can be opened or closed at will; the nasal 
passages are not subject to the will. The left lung 



FIG. 30. FIG. si. 


LUNGS, TRACHEA AND HEART. 

a Aorta, d Arteries. 
b Trachea, vc Veins entering 2. 

2 Right Auricle. 

3 Left Ventricle, with Left Auricle 

above. 

4 Right Ventricle. 

Pulm. Art. and Pulm. Veins. 

(pa and pv, Pig. 25) visible. 


TRACHEA, BRONCHIAL TUBES 
AND LEFT LUNG. 

a Larynx. 
b Trachea, 
c Right Bronchus. 
d Small Bronchial Tubes. 
e Minute Bronchial Tubes. 
(- e l 0 - in diameter.) 


consists of two separate portions called lobes; the 
right lung has three lobes (see Fig. 30). Each lung 
is composed of a soft spongy, elastic substance, and 
is often compared to a bag. Each is attached to one 
of the two bronchi (Fig. SI, c). 






THE RESPIRATORY SYSTEM AND VOICE. 153 


These Bronchi, or Bronchial Tubes, after entering 
the lungs, divide and subdivide into a great number 
of smaller and smaller tubes having a diameter of 
about - 2 L 5 th of an inch (e?), which penetrate to every 
part of the lungs. The trachea and bronchial tubes, 
owing to their cartilages, are unyielding, so as to 
remain permanently open; the finer tubes ( e ), about 
-Jg-th of an inch in diameter, have no cartilages; 
therefore, they may be closed by contraction. The 
minute portion of a lobe is called a lobule; a lobule 
is a little lung of itself. Each minute bronchial 
tube passes into a lobule. After entering the lobule, 
the small bronchial tube divides still further into 
smaller branches (Fig. 32), whose walls at length 
become exceedingly thin. 

The mucous membrane, lin¬ 
ing the air-passages of the 
lungs, has its outside por¬ 
tion covered with peculiar 
cells. Examined under a 
microscope, it is found that 
these cells have extremely 
small hair-like processes, 
called cilia , all in motion, 

waving like a field of grain. Bronchial Tubes, with Air- 

Cells magnified 15 times. 

This motion is towards the 

entrance of the lungs, and probably this is a wise 




154 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

provision of the Creator to carry foreign substances 
from the delicate passages. Each such minute 
branch widens at its end into a caecal air-cell. 

An air-cell, therefore, is a minute cavity of about 
of an inch in diameter (Fig. 36). The air- 
cells are arranged singly, or in groups so that a 
series of cells open into the same bronchial tube. 
The lungs are made up of air-cells. Each air-cell 
carries a network of capillaries — that is, of minute 
blood vessels of about 3 - 0 V 0 aQ inch in diame¬ 
ter ; this net-work is so dense that its open spaces, 
or meshes, are even narrower than the capillaries 
themselves. Between the air in the cells, then, and 
the blood in the capillaries are but two delicate 
membranes, that of the cells and that of the capil¬ 
laries. 

The Trachea, or windpipe (Fig. 12), is a tube of 
cartilaginous nature about an inch in diameter, com¬ 
posed of about twenty cartilaginous rings, beginning 
opposite the fifth cervical vertebra and extending 
down to the top of the breast-bone, where it divides 
into two branches, one leading to each lung, where 
the tubes ramify and divide into numberless smaller 
bronchial tubes. 

The rings of the trachea are complete only in front; 
in the rear, where the trachea rests against the gullet. 



THE RESPIRATORY SYSTEM AND VOICE. 155 


their ends are connected with each other by a thin 
membrane and by muscular fibres. 

An excellent idea of the form of the trachea with 
the bronchi and their ramifications may be obtained 
by comparing their organs with a tree, whose trunk 
represents the windpipe; the two large branches, 
the bronchi ; the smaller branches, the ramifica¬ 
tions of the bronchial tubes, and the buds, the air- 
cells. 

The Larynx (see page 39, Fig. 12) is a cartilagi¬ 
nous tube of conical shape, connecting the 'pharynx 
and the trachea . It is a sort of box, in which the 
vocal cords are placed, whose vibrations produce 
sound. In fact, the larynx is the organ of the voice. 
It contains within its cartilages, immediately below 
the epiglottis, two elastic lips, known as the vocal 
cords. These cords are controlled by certain mus¬ 
cles, so that they can close the larynx against the 
passage of air to or from the lungs. They can also be 
relaxed, or shortened and lengthened, so as to throw 
currents of air passing between them into vibra¬ 
tions— that is, so as to produce sound. During in¬ 
spiration the vocal cords are widely separated; 
during expiration they relax somewhat, and are 
nearer together. Just back of the tongue is an open¬ 
ing, the glottis , leading to the larynx; there is a flesh- 


156 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

like covering over the glottis, called the epiglottis, the 
use of which will be explained later. 

Tlie Pleura is a serous membrane, immediately 
investing the lungs. The walls of the chest are lined 
with a similar membrane. When the lungs are in¬ 
flated, these two membranes move upon each other 
without friction or inconvenience. Being lubricated, 
like other serous membranes, the lungs are thus 
allowed to move smoothly and freely during respira¬ 
tion. 

The bronchi, air-passages, and air-cells have been 
considered under the topic, The Lungs. However, 
it might be stated that the air-passages are composed 
of cartilage and fibro-cartilage, lined with mucous 
membrane. 

The Muscles of Respiration are the Diaphragm 
and the muscles of the chest , abdomen , and bade. 

The Organs of Voice and Their Structure.— The 
Larynx (see page 163, Fig. 34) is the chief organ of 
voice and is made up of seven distinct cartilages: 
Two Arytenoid (pitcher-shaped), two Cuneiform 
(wedge-shaped), one Cricoid (ring-like), one 
Thyroid (shield-like), and the Epiglottis (cover to 
the glottis) explained heretofore. These together 


THE RESPIRATORY SYSTEM AND VOICE. 


157 



A SECTION OP THE MOUTII AND NOSE TAKEN VERTICALLY A LITTLE 
TO THE LEFT OF THE MIDDLE LINE SHOWING PARTS OF THE 
LARYNX. 

a t the Vertebral Column, b, the Gullet, c, the Windpipe, d, 
the Thyroid Cartilage of the Larynx. e t the Epiglottis. /, the 
Uvula soft palate, g, the opening of the left Eustachian Tube, h , 
the opening of the left Lachrymal Duct, i, tne Hyoid Bone. k f 
the Tongue. I , the Hard Palate, m, n, the base of the Skull, o, 
p, q , the Superior, Middle, and Inferior Turbinal Bones. The 
letters g, f, e , are placed in the Pharynx. 





158 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

with some muscles and the vocal cords form the 
voice-box, or Adam’s Apple, so prominent upon the 
front part of the neck. 

The Thyroid is a thin expanded cartilaginous plate, 
bent in the middle, and forming the chief part of the 
Pumum Adami. It is the frame-work for the 
movable portions of the organs of voice. 

The Cricoid , like a seal-ring in form with the broad 
part to the back, is situated on the top of the trachea , 
and forms the base of the larynx. 

The Arytenoid cartilages, the two three-sided 
pyramidal parts, rest upon the upper edge of the 
back part of the Cricoid , and are much more movable 
than the other parts of the larynx, having a ball and 
socket joint. 

The Cuneiform cartilages are about half an inch 
in length with both extremities enlarged. 

The Epiglottis , having the shape of a cordate leaf, 
is fastened by its apex to the upper margin of the 
glottis. It is capable of much motion, and serves to 
deaden sounds. 

The vocal cords are stretched across the middle of 
the larynx just beside the glottis. There are two 


THE RESPIRATORY SYSTEM AND VOICE. 151) 


pair of folds, the upper and the lower, denominated, 
the false cords and the true cords . The false cords 
are fixed. 



FIG. 34. FIG. 35. 


Fig. 34. A side view of the cartilages of the layrnx. *The front 
side of the thyroid cartilage. 1, The os hyoides (bone at the base 
of the tongue). 2, The ligament that connects the hyoid bone and 
the thyroid cartilage. 3, 4, 5, The thyroid cartilage. 6, The 
cricoid cartilage. 7, The trachea. 

Fig. 35. A posterior view of the cartilages and ligaments of the 
larynx. 1, The posterior face of the epiglottis. 3, 3, The os 
hyoides. 4, 4, The lateral ligaments which connect the os hyoides 
and thyroid cartilage. 5, 5, The posterior face of the thyroid 
cartilage. 6, G, The arytenoid cartilages. 7, The cricoid cartilage. 
8, 8, The junction of the cricoid and the arytenoid cartilages. 12. 
The first ring of the trachea. 

The interior of the larynx is lined with a closely 
adhering mucous membrane. The vocal cords com¬ 
posed of a highly elastic tissue are also invested 


160 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


with this same kind of membrane. Lying between 
the true and the false cords is a depression on each 
side of the larynx, named the ventricle. 

3. THE FUNCTIONS OF THE ORGANS OF 
RESPIRATION AND VOICE. 

It has been learned that the lungs are filled with 
bronchial tubes , air-passages and air-cells , and, like 
all tissue having feeling, they contain a vast net¬ 
work of small blood-vessels, called capillaries . 

The purpose of this network of capillaries (see 
p. 165) is to thoroughly expose the blood to the 

action of the 



air. This is 
accomplished : 
(1) By spread¬ 
ing the blood 
over a large 
surface; (2) 
Spreading it in 
thin streams; 
(3) Protecting 
it by merely a 
very delicate 


300 

l 


FIG. 36. 

Fig, 36.— Air-Cells, with Capillaries. 


cover. The renewal of the blood in these capillaries 
is a result of the circulation; the renewal of the 


THE RESPIRATORY SYSTEM AND VOICE. 161 


air in the cells is tne result of respiration. The 
number of respirations is from fifteen to twenty a 
minute, and varies slightly, according to the age. 

Venous blood absorbs oxygen in the lungs through 
the membranes separating it from the air, while at 
the same time it parts with carbonic acid gas and 
watery vapor. This influx of oxygen into, and efflux 
of carbonic acid gas and watery vapor out of, the 
blood form the most important part of the respiratory 
process. They purify the blood in changing it from 
venous into arterial, the means of purification being 
the peculiarly delicate membranes mentioned above. 
(See also page 155.) But the action of the mem¬ 
branes alone would suffice only for a short time, 
since the carbonic acid gas accumulates very rapidly, 
and in large quantity; and also because oxygen is 
needed all over the system at every instant of time. 
Hence we need a rapid removal of the carbonic acid 
gas from the lungs, and at the same time an inces¬ 
sant importation of fresh oxygen. We find that the 
clearing away of the one and the supply of the other, 
are accomplished incessantly by the act of inspiration 
and expiration. The most powerful aids in this 
process are the elasticity of the lungs, the mobility 
of the sides of the chest, and the mobility of the 
diaphragm. The diaphragm is a strong muscle sep- 
Ii 


162 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

arating the chest from the abdomen, thus forming 
the floor of the chest. Its special business is to 
assist respiration. 

To avoid chilling the lungs, cold air should be 
inspired through the nasal passages, not through 
the mouth. 

The inspiration of air into the lungs is effected in 
this way: The lungs are in close contact with the 
inner side of the chest-walls; the lower portion of 
the lungs is in close contact with the diaphragm. It 
is evident that whenever the chest walls move, the 
lungs must also move, and vice versa . So, when the 
chest expands the lungs expand; or, more properly 
speaking, they are enlarged by a quantity of air 
which rushes through the larnyx, trachea and bron¬ 
chi, to fill the lungs. 

In expiration the chest-walls contract; the lungs 
contract likewise — that is, a quantity of air is 
ejected from the lungs and forced to pass through the 
bronchi, trachea, and larynx, this being the only 
communication between the lungs and the external 
air. The act of expiration is followed by a short 
rest. 

The widening and extending of the chest during 
inspiration are owing to the motion of the ribs; the 


THE RESPIRATORY SYSTEM AND VOICE. 163 


lengthening, or deepening of the chest daring 
inspiration, to the descent of the diaphragm. In 
ordinary inspiration both chest and lungs return to 
the state of rest by their elasticity. Ordinary inspir¬ 
ation is nearly exclusively effected by the mobility of 
the diaphragm and the ribs. In very deep inspir¬ 
ation, the dimensions of the chest are increased still 
further by the ascent of the clavicle and the stretch¬ 
ing of the vertebral column. Ordinarily, one 
breathes once to every four heart-beats, which would 
make eighteen breaths per minute, as there are about 
seventy-two heart-beats per minute. 

The rhythm observable in the respiratory process 
is inspiration, expiration, pause; that of the heart 
being, in a similar manner, auricular systole, ven¬ 
tricular systole, pause. 

Functions of the Organs of Voice. — How voice is 
produced is a simple yet interesting process. While 
the process of ordinary breathing is going on, there 
is no voice; because the vocal cords, over which the 
air passes to and from the lungs, are loose and 
inert; but when the cords are tightened, they come 
closer together, nearly filling up the aperture, and 
when very tense, the passage of the air over them 
sets them to vibrating, whereby sound is produced 


164 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

in the same manner as the strings of an Aeolian 
harp will produce music by the passage of the wind 
over them. 

When producing sound, the cords are brought 
within riroth of an inch of each other. A familiar 
example of the modus operandi of voice would be 
seen in placing a blade of grass between the two 
thumbs, and then blowing through the aperture. 
Every youth knows how to do this. 

From physics it is learned that the smaller, 
tighter, and shorter, a vibrating substance is, the 
higher and shriller the sound will be; so is the 
reverse true. Of course the number of vibrations 
also affect the tone. 

The qualities of tone, whereby we notice a differ¬ 
ence in the voices of persons, is probably due to 
the peculiar contour of the larynx, throat, and nose. 

Four varieties of voice* maybe mentioned; two, 


* “Voice is a sound produced in the throat by the passage of 
the air through the glottis, as it is expelled from the lungs. It is 
grave and strong in man, soft and higher in woman; it varies ac¬ 
cording to age. It is alike in both sexes in infancy, but is modi¬ 
fied in youth; then the voice is said to ‘change.’ In the young 
woman it descends a note or two, and becomes stronger. In the 
young man the change is much more strongly marked. At the 
fourteenth or fifteenth year the voice loses its regularity, becomes 
harsh and unequal; the high notes cannot be sounded, while the 
grave ones make their appearance. A year is generally sufficient 




THE RESPIRATORY SYSTEM AND VOICE. 165 


bass and tenor , of the male sex, and two, alto and 
soprano , of the female sex. In man, there is a 
strong, heavy voice, as compared with the soft, 
shrill tones of woman. 

Peculiar Forms of Breathing. — Laughter is an 
involuntary movement of the muscles of the face, in¬ 
dicating joy or merriment, and accompanied by deep 
expulsion of air from the lungs. This is due to a 
spasmodic action of the diaphragm. Sobbing and 
crying are due to the same causes; however, they 
indicate a different state of feelings. Sneezing is 
similar to the foregoing, but caused by the presence 
of some foreign substance in the delicate air-pas¬ 
sages. Sighing is a lengthy inspiration , followed 
by an abrupt expiration of nearly vocalized breath. 

Coughing is analogous to sneezing, differing from 


for this change to be complete, and the voice of the child gives 
place to that of the man. Exercise of the voice in singing should 
be very moderate, if not entirely suspended, while this change is 
going on. Voice is divided into singing and speaking voice. One 
differs from the other almost as much as noises do from musical 
sounds. It is the short duration of speaking sounds which dis¬ 
tinguishes them from those of singing. This is proved by the fact 
that if we prolong the intonation of a syllable, or utter it like a 
note, the musical sound becomes evident.” — Le Pileur on Won¬ 
ders of the Human Body. 



166 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

sneezing in the fact that the convulsive expiration 
drives the air through the mouth, instead of the nose, 
as in the case of sneezing. These irregular breathings 
are chiefly caused by the action of the diaphragm. 
Hiccoughs are caused by a contracted glottis and 
diaphragm, the noise being made by the closed glottis. 
Snoring results from the current of expired air 
striking against the soft palate, and causing it to 
vibrate. 

Moaning is like sighing, but accompanied by vocal¬ 
ized breath. Yawning and gaping come under the 
same head as moaning and sighing . 

Of all these vagaries of respiration, the hiccoughs 
are probably the most serious, as there have been 
cases where it was nearly impossible to stop the 
trouble. 


4. THE AIR. 

The Air We Breathe is a mixture of oxygen and 
nitrogen with a little carbonic acid gas and watery 
vapor. Of these, oxygen supplies life to the body. 
Yet, oxygen is so strong that the body could 
not bear it taken alone ; hence, the nitrogen dilutes 
it (see page 149), while carbonic gas is present as 
an impurity and watery vapor to make the air less 
harsh. The atmosphere surrounds the earth to a 


THE RESPIRATORY SYSTEM AND VOICE. • 167 

depth of 50 miles, and in a highly rarefied degree to 
a depth of 500 miles. Air is necessary to the growth 
of all organic beings, the fish and the plant as well 
as man. 

Pure Air is essential to health. The ozone of the 
seashore is the purest air, having less than .4 of car¬ 
bonic acid, while expired air contains 40 per cent of 
the same impurity. Generally speaking, the air of 
the country is purer than that of the city, and the 
air outside than that inside of a building. 


How the Air is Purified by Nature is another evi¬ 
dence of the Creator’s wisdom. All gases of varying 
specific gravities, when brought into contact, will 
diffuse, or mix, through and through; thus an obnox¬ 
ious gas will be so diffused that it can do little or no 
harm. Every one is aware how much purer the air 
seems after a heavy shower. It is because it has 
been washed. Atmospheric air depends for its purity 
on being washed by rain and dew. It is heated and 
dried by the sun, fed with oxygen by plants, and by 
them also freed of carbonic acid gas. Impure air 
may result from (1) the want of sunlight; (2) the 
want of cleanliness in the household ; (3) the absence 
of efficient ventilation; (4) the presence of dust, 
smoke or decaying matter. It is very dangerous to 


168 * ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the lungs, and although its pernicious effects upon the 
health are generally slow, they are nevertheless 
sure. 

It is a wonderful fact in nature that the plants 
need carbonic acid gas for their growth, while they 
give off oxygen. This is the opposite with animals. 
They need oxygen to sustain life, and throw off car¬ 
bonic acid gas as a waste material. Hence, it is 
observed that the animal and the vegetable kingdoms 
mutually support each other, one giving off what the 
other needs and one requiring what the other throws 
off. The Creator here laid down the great law upon 
which society is based, as well as that other law, 
change is a law of life. 

The Changes of the Air in the Lungs have been 
partially discussed in a former paragraph. In an 
earlier topic also diffusion of gases was spoken of. 
By this process, the air which comes into and fills up 
the lungs loses its oxygen and receives in turn car¬ 
bonic acid gas and watery vapor. This exchange of 
good for evil is due also to a property of membranes, 
termed Imbibition (endosmose and exosmose), by 
virtue of which fluids and gases pass through the 
membranes in opposite directions at the same time. 

Then, to recapitulate, here is the process: The air- 
passages and air-cells of the lungs are filled with pure 


THE RESPIRATORY SYSTEM AND VOICE. 169 


air? the capillaries in the lining of these air-passages 
and air-cells are filled with impure venous blood; 
hence, the delicate membranes only separate the oxy¬ 
gen in the air and the carbonic acid gas and watery 
vapor in the blood. By some unknown affinity, the 
oxygen passes through the membrane to the blood, 
and the impurities of the blood pass through to the 
air. Then the air returns to the outer world with its 
load of death, and the now purified blood rushes back 
through the arteries with its load of life . “ What a 

piece of work is man !” 

The Difference Between Arterial and Venous 
Blood before and after its passage through the lungs 
is shown here: — 


Venous Blood. 


Arterial Blood. 


Color, 

Oxygen, 
Carbonic acid, 
Watery vapor, 
Heat, 

Vitality, 


Dark blue, 

8 per cent, 

About 24 per cent, 
More, 

Less, 

Less, 


Bright red. 

18 per cent. 

Less than 7 per cent. 
Less. 

More. 


More. 


These changes take place in the corpuscles of the 
blood. It might be added that the venous blood 
throws off an inappreciable amount of animal vapor, 
which gives the breath a tainted odor. 


170 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Inspired and Expired Air Differ from each other 
chiefly in the following points: — 

(1.) Expired air has nearly the same temperature 
as the blood, whatever may be the temperature of 
the external air. 

(2.) Expired air is always filled with watery - 
vapor. 

(3.) Expired air always contains more carbonic 
acid gas and less oxygen than inspired air. One 
hundred parts of air breathed once have lost about 
five parts of oxygen, and gained a little less than five 
parts of carbonic acid. This is shown by the follow¬ 
ing statement: — 

Oxygen. Nitrogen. Carb. Acid. 

10,000 parts of atmospheric air contain 2080 7916 4 

10,000 parts of expired air contain (nearly) 1600 7916 484 

The average amount of air at each respiration is 
about 20 cubic inches, which would make daily, 
counting 18 respirations per minute, about 400 cubic 
feet or, in other measures and computations, about 
4,000 gallons. It will be readily seen that this varies 
with the temperature, amount of exercise, and lung 
capacity. Dr. Hutchinson gives the following rule: 
“For every inch of stature from five to six feet, 
eight additional cubic inches of air are given out at 
a forced expiration after a full inspiration.” 

The capacity of the lungs in a person of ordinary 


THE RESPIRATORY SYSTEM AND VOICE. 171 


size is about 320 cubic inches, although the usual 
breathing capacity is only about one-sixteenth of 
that amount, or two-thirds of a pint. Hence, it is 
observed that several breaths must be taken before 
there is a complete change of air in the lungs. This 
is a wise provision as the air cannot be cut off sud¬ 
denly by some interference with respiration, and 
again it would not be healthful for the lungs and 
delicate air-passages to take in 300 cubic inches of 
air at one inspiration, especially were the air cold. 

The Necessities of Ventilation are most apparent 
to modern civilization. The Black Hole of Calcutta, 
the brutal sea-captain, who shut his passengers up 
in a small air-tight cabin during a storm, and the 
more romantic case of Ginevra in the fatal trunk 
with the spring lock are not needed to impress the 
present generation with the importance of right 
ventilation and pure air. 

Since about four hundred cubic feet of air pass 
through the lungs of an adult in twenty-four hours, 
a constant supply of oxygen — that is, of fresh 
a i r — is one of the most essential requirements of 
health. And since carbonic acid gas is unfit for 
inspiration, it follows that every inhabited room 
should have an open space to admit fresh air, and 
an open space to convey away the waste products of 


172 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


respiration ; both spaces must directly or indirectly 
communicate with the atmosphere. But the presence 
of a surplus of carbonic acid is less injurious than 
the absence of the normal amount of oxygen. A 
person living in badly ventilated apartments vitiates 
his blood, predisposes his system to disease, and thus 
virtually shortens his life. A total lack of air would 
result in speedy death.* 

Ventilation is the imperceptible efflux of impure 
air and the simultaneous imperceptible influx of 
atmospheric air. It depends — (1) Upon the differ¬ 
ence of temperature between indoors and out. 
Thus, in severe cold weather, a room, to be well 
ventilated, must be heated. (2) The quantity of 

* We instinctively shun approach to the dirty, the squalid, 
and the diseased, and use no garment that may have been worn 
by another. We open sewers for matters that offend the sight 
or smell and contaminate the air. We carefully remove impuri¬ 
ties from what we eat and drink, filter turbid water, and fas¬ 
tidiously avoid drinking from a cup that may have been pressed 
to the lips of a friend. On the other hand, we resort to places 
of assembly, and draw into our mouths air loaded with effluvia 
from the lungs, skin, and clothing of every individual in the pro¬ 
miscuous crowd — exhalations offensive to a certain extent, from 
the most healthy individuals; but when arising from a living 
mass of skin and lungs in all stages of evaporation, disease and 
putridity — prevented by the walls and ceiling from escaping — 
they are, when thus concentrated, in the highest degree deleteri¬ 
ous and loathsome.— Bmian . 



THE RESPIRATORY SYSTEM AND VOICE. 


173 , 


motion of the atmospheric air. Strong currents of 
air, as winds or storms, greatly facilitate ventilation. 
(3) The size of the orifices through which the air is 
expected to pass. When No. (1) fails, as e. g., in 
summer, we use No. ( 3 ) mostly — that is, we open 
doors and windows. 

Draught is a perceptible current of colder air 
striking, and consequently cooling only a portion 
of the body, usually productive of colds. 

This principle ought to obtain in ventilating 
rooms and houses.* Have an opening near the floor 

* When the win¬ 
dow is of the com¬ 
mon sash kind, a 
good supply of fresh 
air may be obtained 
without a current, 
by placing a strip of 
board about four 
inches wide under 
the lower sash (Fig. 

37). The window is 
thus closed against 
rain and snow, but 
allows a supply of 
fresh air to enter 
between the sashes. 

If still more ventila¬ 
tion is needed to 

keep the air of the of wood beneath lower sash of window. 





























174 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

large enough to allow the pure air to enter and the 
carbonic acid gas (heavier than air) to pass off; then 
an opening near the ceiling to allow vapors to escape 
and to maintain a current through the rooms, as 
much of the impurity has been diffused through the 
air in the room. Every person should have at least 
2,000 cubic feet of air per hour in order to insure 
health, the breathing space being 600 feet. 
Especial care should be taken in properly ventilating 
sleeping apartments. 

Important Facts.— In breathing, a person of aver¬ 
age size exerts a power equal to raising a two hun¬ 
dred pound weight resting upon the chest. The 
length of time one may hold his breath can be greatly 
increased by breathing out all the air possible in 
the lungs, then take several long inspirations in order 
to fill the lungs with pure air. This fact is useful 
to know in going through smoke or fire, or in the 
case of diving. It is said that pearl fishers, by long 
practice, have been able to remain under water 
for three or four minutes. Ordinarily, thirty sec¬ 
onds are long enough to hold the breath. Every 
fifth breath seems to be deeper and stronger than 
the four preceding ones. Nearly all the blood in 


room sweet, the same arrangement may be made at the top of 
the window.— Hutchison. 



THE RESPIRATORY SYSTEM AND VOICE. 175 


the body reaches the air in the lungs every two and 
half minutes. The lungs daily (24 hours) throw 
off from eighteen to twenty-five ounces of watery 
vapor, and from two to three pounds of carbonic 
acid gas, both depending upon the temperature, 
exercise, age, sex, and general health. Air that 
contains more that 3^- per cent of carbonic acid gas 
is injurious. By constant practice in taking full 
respirations a portion of each day, one may develop 
his chest measure many inches. 

The parrot, magpie, and raven may be taught to 
speak by rote, but man alone has the power of 
speech proper. The range of the human voice is 
said to be four octaves. The wonders of the Phono¬ 
graph, Telephone, and Graphophone are marvelous. 
What has science in store for us? 


6. HYGIENE OF THE RESPIRATORY 
SYSTEM. 

Respiration by Means of the Skin. — Through the 
skin of the body, oxygen of the air enters and 
passes to the blood; and carbonic acid gas and 
watery vapor emerge through the skin from the 
body. The quantity of watery vapor perspired in 
twenty-four hours amounts to about 2 pounds. 


176 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

The proper supply of oxygen forms one of the 
three most important requirements for health. (For 
the other two see pp. 110 and 150.) 

The Lungs Need Action as well as pure air. 
Hence, full inspirations fill the remotest air-cells. 
This can be done by raising the chin, throwing back 
the shoulders, and drawing in a long breath. Ex¬ 
hale slowly. Persons of sedentary habits should do 
this several times a day. Try this daily for months 
and note the effect. 

The Injurious Effects of “ wet feet,” and of 
garments moistened from rain, or from having been 
worn next to the skin too long, are due to the cold 
produced by evaporation, and also to the greater 
conductive power of water. The skin must be kept 
warm, and free from moisture; garments worn next 
to the skin should be frequently changed. A person 
who, with his body heated from exertion or rapid 
motion, and perspiring copiously, should enter a 
colder atmosphere, or be exposed to a draught, would 
lose an enormous quantity of heat, both by conduc¬ 
tion and radiation. 

Diseases resulting from “colds” are among the 
most painful and dangerous. The process of “ cool¬ 
ing off” should at all times be carried on slowly and 
gradually. 


THE RESPIRATORY SYSTEM AND VOICE. 


177 


Warm Moist Air Is Best for breathing, as cold, 
damp air is apt to irritate the lungs. Very hot air is 
injurious. 

The Organs of Speech need plenty of exercise in 
order to develop strength. Habitual practice upon 
the vowels, sounding them positively, will tend to 
strengthen the organs. The habit of saying mornin 9 
for morning is unpardonable. Such slovenness in 
speech is due to laziness. Americans are more care¬ 
less in this respect than Englishmen.* 


SOME HYGIENIC RULES REGARDING CLOTHING, ETC. 

The Normal Condition of the Body should be 
maintained at all times, whether the temperature of 
the atmosphere be low or not. This is effected (1) 
by clothing, (2) by the bed, (3) by buildings. 

(1.) Clothing .— Our garments act like so many 
artificial skins, and thereby protect the skin from the 
injury which would result to it were it left exposed 
to the changing habits of our climate. They lose 
heat in place of the skin; they sustain intense cold 
or heat, rain and storm, in order that the delicate 


* Speak the speech trippingly on the tongue.— Hamlet. 
\Z 



178 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

vessels of the skin may not be contracted by cold or 
expanded by heat, and the nerves not be shocked. 

As the garments worn next to the skin are con¬ 
stantly moistened by perspiration, their water¬ 
absorbing qualities should be consulted. And since 
moist fabrics are better conductors of heat than dry 
ones, such garments must be frequently changed. 

Linen is a rapid absorbent of moisture. As the 
moisture absorbed readily evaporates, and thereby 
produces cold, and as linen is also a good conductor 
of heat, it is a favorite article of clothing in summer ; 
but it should never be worn next to the skin. 

Cotton neither absorbs as much moisture, nor 
conducts heat as well, as linen. It is, therefore, 
warmer, although much cooler than either wool or 
silk. 

Woolen is a great absorbent, which does not give 
up its moisture so readily as the preceding fabrics. 
This property makes it very valuable. It is a bad 
conductor on account of the great quantity of air 
contained within its meshes. It also possesses the 
property of condensing watery vapor within its tis¬ 
sue, and thus produces warmth. This explains why 
fresh flannel, put on after great exertion, feels so 


THE RESPIRATORY SYSTEM AND VOICE. 179 


warm. It should at all times be worn next to the 
skin. 

(2.) The Bed .— This is the sleeping apparel during 
nearly one-half of our life, and as important as cloth¬ 
ing. It is made of material similar to that of gar¬ 
ments and serves the same purpose. But it must be 
made much warmer than our clothing, because (a) 
the body develops less heat during sleep, and must 
yet be maintained at its standard temperature; (5) 
the body, when not lying down, is heated by currents 
of heated air ascending from the feet to the neck, 
while when stretched out horizontally the body is not 
so heated, for these currents then ascend perpendicu¬ 
larly from the body. Some one has facetiously said 
that there should be seven hours of sleep for a man, 
eight for a woman, and nine for a pig. 

(3.) Buildings .— Dwelling Houses serve the same 
purposes as clothing, which they also resemble in 
this: that, as a rule, they are built of badly conduct¬ 
ing material. Like clothing, the walls of buildings 
should always be permeable to air. As long as they 
are in good condition they are easily penetrated by 
atmospheric currents. This is evident, for we know 
that wood, brick and stone are more or less porous, 
and that they readily absorb water; now, wherever 


180 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

water can penetrate, air, being so much lighter, can 
enter in hundredfold quantities; the fact that we 
never feel air pass through walls means nothing, 
since currents of air moving at a rate less than 
about 20 inches a second are not felt by the nerves. 

Moist Walls are unhealthful for the same reasons 
as those applying to moist garments: (a) The stop¬ 
page of ventilation, the pores of the walls being taken 
up by water to the exclusion of air; ( b) The cold- 
producing effects, owing to increased radiation and 
conduction to heat the water ; (c) The cold generated 
by the evaporation of the moisture. 

Large Quantities of Water are contained in the 
mortar of the walls in newly erected buildings. 
Most of this water must be first removed before the 
dwelling is fit to be inhabited. It is removed best by 
giving it sufficient time to evaporate, and promoting 
the evaporation by means of artificial heat and by 
removing the vapor by ventilation. 


THE RESPIRATORY SYSTEM AND VOICE. 


181 


REVIEW QUESTIONS. 

1. Have you read Holmes’ The Living Temple ? 

2. What system deals with the blood, its travels, etc.? 

3. Where are the air and the blood brought into close contact? 

4. What are the offices of respiration? What does man re¬ 
quire aside from food in order to live? 

5. Give the composition of air. For what purpose is nitrogen? 

6. What is the temperature of the human body? What would 
a decrease of five degrees F. of animal heat produce? 

7. Give one of the most important requirements of health. 

8. In what three ways may heat be lost? Explain each? 

9. Why is a wooden handle put upon an iron poker? Why 
should wet clothing be changed at once ? 

10. Why do we “catch cold” more easily in moist, cold weather 
than in dry and cold? 

11. Name the “ Organs of Respiration.” Which may also be 
considered organs of voice? 

12. What are the two kinds of blood? Where does the blood 
change from impure to pure? 

13. Describe the lungs. Through what passage do they re¬ 
ceive air? 

14. Describe the bronchial tubes. In what do they end? 

15. What are the cilia? Give their purpose. 

16. With what are the air-cells lined? What are capillaries? 

17. Locate and describe the trachea. From what may a good 
idea of the trachea be obtained? 

18. Give a general description of the larynx. 

19. Give structure of the pleura. Why does it seem so 
smooth? 


182 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


20. Explain the relation of trachea and the bronchi. 

21. Name the muscles of respiration. What is the chief one? 

22. Name the organs of voice. What one was given under organs 
of respiration? 

23. Name the parts of the larynx. What is Adam’s Apple? 

24. Describe briefly each cartilage forming the larynx. 

25. What is the purpose of the vast net-work of capillaries in 
the lungs? 

26. What is the most important part of the respiratory pro¬ 
cess? 

27. Why must the carbonic acid gas be removed rapidly? 

28. How may one avoid chilling the lungs? 

29. Explain fully the process of inspiration. Of expiration. 

30. What is the rhythm in the respiratory process? Of the 
heart? 

31. How is voice produced? How do the vocal cords produce 
sound? Explain the example of the blade of grass and the 
thumbs. 

32. How many varieties of voice are there? State what is 
quoted from " Le Pileur on Wonders of the Human Body.” 

33. Name the peculiar forms of breathing, giving the cause of 
each. 

34. What is air? Give its composition, and depth upon the 
earth. 

35. What is the purest air? How does nature purify the air? 

36. What are the changes which air undergoes in the lungs? 

37. Give the table showing differences in venous and arterial 
blood. Also, the table showing how inspired and expired air 
differ from each other. 

38. Give the amount of air at each breath. How much air is 
used in 24 hours? Give Dr. Hutchinson’s rule. 

39o What is the capacity of the lungs? How long does it 
require for the lungs to be fully refilled? 


THE RESPIRATORY SYSTEM AND VOICE. 


183 


BLACKBOARD OUTLINE. 


VI. THE RESPIRATORY SYSTEM AND VOICE, 


1. The Introduction. 

a. Uses of Respiration. 

b. Relation of Circulation and Respiration. 

c. Composition of Air. 

d. Animal Heat and Bodily Temperature. 

e. How the Heat of the Body May Be Maintained. 

( Conduction, 

f. Heat May Be Lost By 1 Radiation, 

(Evaporation. 


2. The Organs of Respiration ami Voice—Their Structure. 

a. General Discussion. 


The Organs of 
Respiration 
and Voice. 


f f The Lungs, 

I The Air Passages, 
| The Pleura, 

Of Respiration^ The Larynx, 

The Trachea, 


l 

c. The Structure of Same. 


The Bronchi, f 2 Arytenoid, 
[ The Muscles. 2 Cuneiform, 
The Larynx, < 1 Cricoid, 

Of Voice. ^ The Vocal Cords, 1 Thyroid, 

(The Muscles. 1.1 Epiglottis. 
Of Respiration. 

Of Voice. 


3. The Function of the Organs of Respiration and Voice. 


4. 


a. Of Respiration. 

b. Of Voice. 

f Laughter, 

Peculiar Forms of Breathing. fneez^ng^^ ^ rying ’ 

(.Sighing and Moaning,etc. 


The Air. 


'Amount of Atmosphere, 

Pure Air — How Made, 

The Change in the Lungs, 
Difference Between Venous and 
Arterial Blood as Produced 
"| by the Effect of the Air, 

Tables of Comparison, 

Capacity of the Lungs, Number 
of Respirations per Minute,etc., 
LThe Necessities of Ventilation. 


Important Facts. 


5. Hygiene of 


a. Hygiene. 


the Respiratory System and Voice. 
Respiration Through the Skin, 

Lungs Need Action, 

The Injurious Effect of Wet Feet, 
Warm, Moist Air, 

The Organs of Speech, 
l. Rules Regarding Clothing and Shelter 















THE DIGESTIVE SYSTEM. 


Some will have it that the stomach is a mill; others that it 
is a fermenting vat; and others that it is a stewpan; but in 
my view of the matter, it is neither a mill, a fermenting vat, 
nor a stewpan, but a stomach, a stomach !—Sir John Hunter, 




FIG 38 . 


( 186 ) 



* 
































































































THE DIGESTIVE APPARATUS (HENLE, AN AT.). 

Head and Neck turned toward the right. 


Front View 

T Trachea. 

(j Oesophagus, Gullet. 
a Cardia. 

S Stomach. 
b Pylorus. 

P Pancreas. 

D Duodenum. 

Dp Small Intestines laid aside. 
Jejunum. 

Ileum. 


t Left Lobe of Liver cut off 
C Caecum. 

va Vermiform Appendix. 

Co Colon. 

R Rectum. 

L Liver. 

1 Gall Bladder. 

2 Diaphragm. 
sp Spleen. 


( 187 ) 




















VII. The Digestive System. 


1. INTRODUCTION. 

The Human Body is a machine, wnose parts 
are so nicely designed and fitted that were the 
proper care taken it would work on through man’s 
allotted span of “ three score and ten,” and yet 
not be “ run down.” In all its varied movements 
and manifold motions of its different parts, together 
with its great number of functions, the body is 
supported and maintained by an energy, whose 
source is food , physically and chemically prepared 
to give power and action to this living, moving, 
working machine. No human contrivance, no 
matter how nicely and perfectly adjusted in all 
its parts, works so smoothly, silently, and har¬ 
moniously, with such precision and completeness, 
as the human organism, which is indeed “ fear¬ 
fully and wonderfully made.” Hence, from the 
moment it enters the mouth to begin its prepa¬ 
ration to become the force, that supplies the 
energy that fells a tree or brings into being a 
law of gravitation, to that supreme moment after 

(189) 


190 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


it has passed the mysterious laboratories of the 
body, — the following pages will consider food 
under the broader subject of the digestive system . 

The Food of Plants requires no modification pre¬ 
vious to its being absorbed by the vegetable 
organism. Plants feed principally on water, car¬ 
bonic acid, ammonia, and saline substances, all of 
which they find ready for their absorption. Man 
and animals, however, derive their food principally 
from organic substances. They prepare it within 
their bodies before it is absorbed by the blood; 
and man, in addition, cooks his food. 


The Changes Wrought Upon the Food in the body 
may be divided into three parts: (1) Digestion, 
or the proper preparation of food in the ali¬ 
mentary canal so as to fit it for absorption. 
(2) Absorption and Assimilation, or the conver¬ 
sion of food into blood and tissue. (3) Excretion, 
or the decomposition of food and its removal 
from the body. With the exception of the lungs, 
which absorb oxygen, the alimentary canal is 
generally the only channel by which food can 
pass into the blood. 


THE DIGESTIVE SYSTEM. 


191 


2. THE ORGANS OF DIGESTION. 

The Organs of Digestion are the Mouth , Teeth , 
Salivary Glands , Pharynx , Oesophagus , Stomach , 
Intestines , Lacteals , Thoracic Duct , Liver , Gall-cyst , 
Pancreas , and Spleen . 

The Kidneys may be classed here, although they 
do not belong to the Digestive System . 

3. THEIR STRUCTURE. 

The Mouth (see page 198, Fig. 38) is the irregular 
cavity, containing the organs of mastication and 
taste. It is the mill in which the food is ground. 
In fact, it is the preparation room for the material 
soon to pass through the oesophagus to the chemical 
work-shops of stomach, intestines, etc., on into the 
blood. 

The Teeth (page 26, Fig. 6) are 
the bone-like bodies implanted in the 
upper and the lower jaw. 

While the structure of the teeth 
belongs to a previous chapter, it may 
be interesting here to refer to the fig. 39 . 
adaptation of teeth in different Jaws of a 





192 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

classes of animals to the food upon which the 
animal subsists. Thus, in fish, the food is swal¬ 
lowed entire; hence, the teeth have, as a lule, 
the form of sharp, curved spines (Fig. 39). Such 
teeth merely serve the purpose of retaining or 
holding the prey. The horse has incisors in both 



jaws (Fig. 40), while herbivorous animals of the 
ruminating order have their incisors only in the 
lower jaw. These incisors merely serve to cut 
off the grass or herbs upon which the animal 
feeds. The process of mastication is performed en¬ 
tirely by the molars, the canines being either want¬ 
ing or only imperfectly developed. Carnivorous 
animals, such as the bear or dog, have incisors for 
dividing the food, canine teeth for attacking and re- 



THE DIGESTIVE SYSTEM. 


193 


taining the prey, and molars for grinding (Fig. 6). 
In man the teeth are so selected as to combine the 
features of those of the herbivorous and the car¬ 
nivorous animals, which distinctly points to the fact 
that his food should be composed both of animal 
and vegetable substances. 

The Salivary Glands are six in number, two par¬ 
otids , two submaxillaries , and two sublinguals , there 
being three on each side of the lower jaw. The 
largest of these are the two parotids , which lie, one 
on each side, just back of the angle of the jaw and 
directly in front of the external ear. These glands 
are affected in mumps. The ducts from the parotids, 
one from each, reach the mouth, opposite the second 
molar of the upper jaw. 

The two submaxillary glands , one On each side of 
the lower jaw, are situated just in front of the angle 
of the lower jaw, and their ducts, one from each, 
enter the mouth by the side of the frcenum linguae . 
or the bridle of the tongue. 

The sublingual glands , also two in number, are 
situated in the floor of the mouth, one on each side of 
the frcenum linguae . These glands have several 
ducts opening into the mouth. 

13 


194 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

The Salivary Glands , together with the Mucous 

Glandule s in the 
mucous lining of the 
mouth, produce fluids 
whose uses in diges¬ 
tion will be clearer 
later on. They are 
made up of bunches 
of small pouches, 
covered with a net¬ 
work of blood-ves¬ 
sels. 

The Pharynx is the short cylindrical cavity be¬ 
tween the mouth and the oesophagus. Passages 
enter the pharynx from the mouth, the ears, the 
nostrils, and the lungs. It is made up of muscular 
fibre running in two directions. The pharynx is to 
the oesophagus what the larynx is to the trachea. 

The Oesophagus, or gullet, is a large membranous 
tube that extends behind the trachea, the heart, and 
the lungs, passes through an opening in the dia¬ 
phragm, and terminates in the stomach by the cardiac 
orifice. 

The Stomach is the principal organ of digestion, 
and serves for the solution and digestion of the food 



THE DIGESTIVE SYSTEM. 


195 


into chyme. It is situated in the left side of the 
abdomen immediately below the diaphragm, inclining 
obliquely downwards from the left to the right. It 
has two openings: one connected with the oesoph¬ 
agus, called the cardiac orifice , which is always 
open ; the other connected with the upper portion of 
the small intestine, called the pyloric orifice , which 
is firmly closed so as to allow only the finest pulp to 
pass. It is provided with a multitude of small 
glands, in which is secreted the gastric juice. The 
stomach is the continuation of the gullet, but it is 
much wider, and of different forms in different ani¬ 
mals. It is a sort of bag of about one and a quarter 
square feet interior surface, with a capacity of four 
pints, and a weight of seven ounces, in the adult man. 

The stomach has three coats: the exterior, known 
as the serous coat, is very strong, and invests every 
part of the organ ; the middle, or muscular coat, is 
composed of two layers of fibres, one set of which 
is arranged circularly, and the other longitudinally. 
The interior is the mucous coat, and is arranged in 
folds, called rugae. 

The Intestines are divided into the small and the 
large ; the former being about twenty-five feet in 
length, and the latter about five feet. They are each 
subdivided into three parts, with the names of duode - 


196 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

num, jejunum , and ileum for the small; and ccecum, 
colon 9 and rectum for the large. 

The intestines (Fig. 38) are the continuation of the 
stomach. They form a long, narrow tube, which, 



fig 42. 


THE INNER SURFACE OF THE STOMACH AND DUODENUM. 

1. The lower portion of the oesophagus. 2. The opening 
through which the food is passed into the stomach. 8. The 
stomach. 9. The opening through which the food passes out of 
the stomach into the duodenum, or upper portion of the small 
intestine. 10, 11, 14. The duodem. 12,13. Ducts through which 
the bile and pancreatic fluid pass into it. a, 6, c, the three 
coats of the stomach. 

like the stomach, is composed of membranous, mus¬ 
cular, and mucous coats. The intestines are of 
different lengths in different orders of animals. 

The alimentary canal begins with the mouth and 


THE DIGESTIVE SYSTEM. 


197 


terminates with the rectum. Its entire length is 400 
inches, nearly, of which about 240 inches belong to 
the small intestine. The small intestine has many 
windings, is indirectly attached to the spinal column, 
and fills the lower central portion of the ventral 
cavity. The order of its parts is: duodenum, D, 
jejunum, j, and ileum, i, which are one, nine, and 
fifteen feet in length, respectively. 

The small intestine possesses a regular motion in 
the direction of its own course; this motion is called 
peristaltic , and consists of muscular contractions, 
such as take place in the gullet, the purpose of which 

is, to propel the food onward to the lower parts and 
into the large intestines. 

The duodenum , sometimes called the second 
stomach on account of the digestion taking place in 

it, is so called from its being about twelve finger 
lengths long. It begins at the pyloric orifice of the 
stomach and extends backwards and upwards until it 
ends in the jejunum. The jejunum also has the three 
coats, which are slightly pinkish in color, the mucous 
membrane being thicker than in any other of the 
intestines. The jejunum is so called from a French 
word meaning “ empty,” as that is the condition in 
which this intestine is always found after death. 

The ileum , meaning to twist, is the third section of 


198 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the small intestine, and is darker in color than the 
other divisions. 

The large intestine , about five feet long, is shorter 
but wider than the small intestine. It has three 
subdivisions: the caecum , C, the colon , Co, and the 
rectum , R. They are respectively three inches, four 
feet, and seven inches in length, these varying in 
different individuals. The caecum, which has a gray¬ 
ish blue color, is the short portion below the junction 
of the small intestine (the connection being made by 
a valvular arrangement allowing the food to pass into 
the caecum from the ileum), and distinguishable by a 
vermiform appendix, v, a , about three inches in 
length. The continuation of the caecum forms the 
colon, meaning “to prohibit” as the food passes 
slowly through this portion, which rises on the right 
side of the abdomen up to the liver. This portion of 
it is the ascending colon. The colon then suddenly 
turns at a right angle and crosses over to the left side 
of the body; this horizontal part of it is called the 
transverse colon; finally, it makes a sudden turn 
downward and backward along the left side of the 
body, where, accordingly, it is called the descending 
colon , which is succeeded by the rectum, R, meaning 
straight, owing to its position. The large intestine is 
readily recognized by its width, its stretching capac- 


THE DIGESTIVE SYSTEM. 


199 


ity, and its many folds and pouches. Its motions are 
far slower than those of the other intestine, and 
scarcely ever result in actual displacements of the 
parts with reference to each other, such as take place 
in the small intestine. 

The Omentum, or Caul, is the serous membrane of 
four layers, enveloping the viscera of the abdomen, 
protecting them from cold and violence. It is the 
folds of the peritoneum. 



FIG. 43. 

THE LIVER TURNED UP AND VIEWED FROM BELOW. 

a, Vena Cava, &, Vena Portae. c, Bile Duct, d, Hepatic Ar¬ 
tery. I, Gall Bladder. The termination of the Hepatic vein in 
the Vena Cava is not seen, being covered by a piece of the Vena 
Cava. 

The Liver is a large dark, red-colored glandular 
body (covered by a coat of peritoneum), the largest 







200 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

organ ill the system, and weighs about four pounds 
and measures twelve inches in its longest diameter. 
It is situated toward the right side of the abdominal 
cavity, and is retained in its place by several liga¬ 
ments. It is composed of five lobes which in turn 
are divided into smaller bodies, or lobules, about the 
size of cabbage seeds, each lobule containing an art¬ 
ery, veins, and a net-work of ducts. Its upper sur¬ 
face is convex and its under concave. It performs 
the double office of separating impurities from the 
venous blood and of secreting bile. On the under 
surface of the liver is a membranous sac, called 
the gall-bladder, which is the reservoir for the bile. 

The Gall-cyst (Fig. 43) is a small membranous sac, 
upon the under surface of the liver 9 containing about 
two ounces, and receiving the bile from the net-work 
of ducts in the liver. It has a passage to the duode¬ 
num, called the bile-duct. 

The Pancreas (“ all flesh”) and Spleen are 
glands of the same system, both having their share 
in the process of digestion. Th q pancreas is a long, 
flattened gland, about seven inches in length, weighs 
three or four ounces, and is situated transversely 
across the posterior wall of the abdomen, immediately 
behind the stomach. It has the lobular structure 


THE DIGESTIVE SYSTEM. 


201 


similar to the liver; but each lobule is made up of 
smaller lobules. The secretion of this gland passes 
through its duct into the duodenum. 



FIG. 44. 


SPLEEN AND CONNECTING ORGANS, 

The Spleen, Spl., with the Splenic Artery. JSp. A, Below this is 
seen the Splenic Vein running to help form the vena portae, V. P. 
Ao.j the Aorta. D., a pillar of the diaphragm. P. D., the Pan¬ 
creatic Duct exposed by dissection in the substance of pancreas. 
Dm., the Duodenum. B. D ., the Billiary Duct uniting with the 
pancreatic duct into the common duct, x, y , the Intestinal Ves¬ 
sels. Ps. Pancreas. 

The Spleen (Fig. 44) is an oblong, flattened organ, 
situated in the left side close to the diaphragm, 
stomach, and pancreas. It has a dark bluish color, 
with an abundance of blood, but, unlike the liver 




202 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

and pancreas, it has no duct. Its use has long been 
an object of conjecture although it is now supposed 
to have something to do with the white corpuscles 
of the blood. 

The JLacteals.— The Lacteals are minute vessels, 
which commence in the villi, upon the mucous sur¬ 
face of the small intestine, beginning like the small 
veins and acting as absorbents. From the intestine 
they pass between the membranes of the mesentery to 
small glands about the size of peas which they enter. 
The first range of glands collects many small vessels, 
and transmits a few larger branches to a second range 
of glands ; and, finally, after passing through several 
successive ranges of these glandular bodies, the lac¬ 
teals, diminished in number and increased in size, 
proceed to the enlarged portion of the thoracic duct, 
into which they open at or about the last dorsal ver¬ 
tebra. They are numerous in the upper portion of 
the small intestine. 

The Thoracic Duct commences in the abdomen, by 
a considerable dilatation. From this point, it passes 
through the diaphragm, and ascends to the lower part 
of the neck keeping close to the spinal column and 
sometimes for an inch or two separating into two 
ducts, then uniting again. At the lower part of the 


the digestive system. 


203 



FIG. 45. 

A PORTION OF THE SMALL INTESTINE, LACTEAL VESSELS, 
MESENTERIC GLANDS AND THORACIC DUCT. 

1, The intestine. 2, 3, 4, Mesenteric glands, through which 
the lacteals pass to the thoracic duct. 5, 6, The thoracic duct. 

7, The point in the neck where it turns down to enter the vein at 

8. 9, 10, The aorta. 11, 12, Vessels of the neck. 13, 14, 15, 
The large veins that convey the blood and chyle to the heart. 
16, 17, The spinal column. 18, The diaphragm (midriff). 



204 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


neck, it makes a sudden turn downward and forward, 


and terminates by opening into a large vein, called 
the left subclavian , which passes to the heart. The 
thoracic duct is equal in diameter to a goose-quill, 
and, at its termination, is provided with a pair of 


semi-lunar valves, which prevent the admission of 



FIG. 46 . 

KIDNEYS, URETERS AND 
BLADDER. 


venous blood into its cylinder. 

The lacteals and thoracic 
duct have three coats. 

The Kidneys are the two 
bean-shaped bodies about five 
inches long, two and a half 
inches wide, and one inch in 
thickness. They are red¬ 
dish yellow in color, and are 
situated in the lower part of 
the back, one on each side of 
the lumbar region of the 
spine. From the middle of 
the concave side of each kid¬ 


K, the kidneys; Ur., ure¬ 
ters; Ao., aorta; V. C. I., 
vena cava inferior, and the 
renal arteries and veins. 
Bl., the bladder, the top of 
which is cut off so as to 
show the openings of the 
ureters (1, 1) and that of 
the urethra (2). 


ney, a long small tube, the 
ureter , proceeds to the blad¬ 
der. The latter, situated in 
the pelvis, is an oval bag, 
the walls of which contain 
abundant unstriped muscular 




THE DIGESTIVE SYSTEM. 


205 


fibre, while it is lined, internally, by mucous membrane 
and coated externally by a layer of the peritoneum, 
or double bag of serous membrane, which has exactly 
the same relations to the cavity of the abdomen and 
the viscera contained in them, as the pleurae have to 
the thoracic cavity and the lungs. The ureters open 
side by side, but at some little distance from each 
other, on the posterior and inferior wall of the 
bladder. A single aperture leads into the canal, 
which is called the urethra , by which the cavity of 
the bladder is placed in communication with the 
exterior of the body. 

4. THE PROCESS OF DIGESTION, 

Since the location and structure of the organs of 
digestion have been fully set forth, the various trans¬ 
formations, or steps, through which the food passes 
from mastication to assimilation , will be the logical 
order of arrangement, and the whole process takes 
place in the alimentary canal, where the food is sub¬ 
jected to the action of two forces, one physical and 
the other chemical , whose useful and final effects will 
be discussed in the present topic— The Process of 
Digestion. 

Digestion Begins in the Mouth, where tho food 
is thoroughly chewed, crushed, and ground by the 


206 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

teeth (see p. 26), which are assisted in this work by 
the tongue and cheeks. 

The tongue has the function of holding back the 
portion of aliment which is about to pass down not 
yet wholly crushed by the teeth; and any particles 
of food which have been pushed outside of the teeth 
are thrust back again under the teeth by the com¬ 
pression of the lips and cheeks. The tongue also 
crushes soft substances against the palate. It is, at 
the same time, an organ invested with special mo¬ 
bility and acute sensibility, so as to pass judgment 
upon the qualities, situation, and degree of trituration 
of the aliment in the mouth. The combined action 
of the teeth, tongue, lips, and cheeks results in the 
breaking down of the food. The purpose of this is, 
that the food shall present a large surface to the 
dissolving action of the various fluids acting upon 
it. If large masses were to pass down unbroken by 
the teeth, they would scarcely be altered in the 
stomach, and consequently supply nutrition imper¬ 
fectly. 

In chewing the lower juw does the chief part of the 
work, as the upper has little motion, being only a 
point of resistance. These motions might be classed 
as up-and-down, or cutting; a side, or grinding , and 
backward and forward, or gnawing . This reduction 
of the food to a fine condition is called mastication. 


THE DIGESTIVE SYSTEM. 


.207 


Insalivation, or the Mingling of the Saliva with 
the food during the process of mastication , may be 
termed the second step in this digestive process. In 
another portion of this chapter, the salivary glands 
were discussed. Now, these glands as well as the 
mucous lining of the mouth secrete a colorless, 
frothy, watery-like fluid, called saliva , which has the 
peculiar property of changing starch into sugar , while 
air, contained in the bubbles of the saliva, is also 
mingled with the' food. Saliva is alkaline in its 
nature; contains ptyalin, which is the active principle 
that converts the starch into sugar. The amount 
of saliva daily secreted is about five pounds. 

The presence of food in the mouth, or even the 
smell or taste of the same, will excite the salivary 
glands, causing them to act. 

Too much stress cannot be laid upon thorough 
mastication and insalivation; for only during these 
steps and that of deglutition is the food under man’s 
control, and the ease of digestion depends upon the 
first two steps. In short, the uses of saliva may be 
summed up as follows :— 

(1.) To soften the food so that the gastric juice 
will attack it more readily. 

(2.) To aid articulation and taste by keeping the 
mouth moist. 


208 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

(3.) To quench thirst. 

(4.) To facilitate mastication and deglutition by 
moistening the food. 

(5.) To change the starch of the food into sugar, 
thus fitting the food for digestion. 

Deglutition, or the Act of Swallowing — the third 
part of digestion — takes place after the aliment, by 
means of mastication and insalivation, has been 
reduced to a minute pulp, and is passing it from the 
mouth through the oesophagus, or gullet, to the 
stomach. When the food has been thoroughly 
reduced and mixed with saliva, it is placed upon the 
rear of the tongue, from which it is forced into the 
pharynx where it is seized by other muscles, and 
rapidly moved past the glottis into the oesophagus. 
This downward passage is effected by a successive 
contraction of the muscular parts around the oesoph¬ 
agus above the food, while they are lax below. 
Hence it is that a man can drink standing on his 
head; and a horse with its head lower than its 
stomach. Food, while in the mouth, is controlled by 
the will, but deglutition is not. 

The Oesophagus secretes an oily fluid that keeps its 
surface well lubricated. As soon as the food enters 
this passage, it is forced on into the stomach by the 


THE DIGESTIVE SYSTEM. 


209 


alternate contraction and relaxation of the lings of 
the gullet, which have been described elsewhere. 
The food now passes from the cardiac orifice into the 
stomach, where its changes will next be considered. 

The Stomach Digestion is the fourth step ill this 
process. As soon as the food reaches the stomach, 
the gastric juice, a clear, colorless, acid exudation 
from millions of minute tubes in the inner walls of 
the stomach, begins to flow and to moisten the 
mucous membrane of the stomach, thoroughly mix¬ 
ing with the food which is thrown from side to side, 
round and round, by the alternate contraction and 
relaxation of the middle coat of the stomach. 

This muscular coat is made up of involuntary 
muscles; it is these which perform the mechanical 
labor of kneading and rolling about the pulp. The 
food is pushed on along the great curvature of the 
stomach (on the left side of the body) to the right, 
and thence to the left along the lesser curvature. 
The continual rolling motion, called the peristaltic 
motion, together with the continual addition of gastric 
juice, finally reduces the food to a fine pulp of a con¬ 
sistency somewhat like that of thick soup, and is 
called chyme . The reduction of food to chyme is 
called chymijication. The stomach is not capable of 
great muscular effort; hence it cannot crush, e. g. an 
H 


210 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

entire grape. The violence of abdominal motion in 
vomiting is not due to the effort of the stomach 
alone, but to the co-operation of abdominal muscles. 

The interior coat of the stomach contains a great 
number of glands which open upon its surface. 
Some of these are in the vicinity of the pylorus, 
and secrete a mucous substance which covers the 
interior surface of the stomach, and serves to 
envelop undigested pieces of food so as to facilitate 
their passage through the intestines* The others, 
which form by far the greater number, secrete the 
gastric juice. This fluid has an extraordinary sol¬ 
vent power on albuminous and other substances; 
one part of it in 60,000 parts of water will be 
sufficient to exert this power. It does not act upon 
fatty substances further than liquefying them. It 
is readily precipitated by alcohol; this may explain 
the pernicious effect upon the stomach, caused by 
the use of alcoholic drinks. 

The gastric juice has three properties: the acid, 
the fermentative, and the antiseptic. The acid dis¬ 
solves different food materials; the fermentative, due 
to a peculiar property termed pepsin, produces lactic 
fermentation, while the antiseptic prevents putre¬ 
faction. The albuminoids (the fats and sugars be¬ 
ing only slightly affected) which are affected by the 
gastric juice, are transformed into a product termed 


THE DIGESTIVE SYSTEM. 


211 


albuminose (chyme), which, with water, salt, and 
fruit sugar is readily absorbed by the blood-vessels 
of the stomach. The remainder of the unabsorbed 
and undigested albuminose passes the pylorus, “ gate¬ 
keeper/ ’ into the duodenum, where it is mixed with 
the bile and the 'pancreatic juice. The food under¬ 
goes its most important changes in the stomach. 
The stomach daily secretes nearly fifteen pounds of 
gastric juice . Much of it, if not all, is reabsorbed 
by the walls of the stomach after its duty is 
done. 

Chyme, as it leaves the stomach, is composed 
of — 

(1) Albuminous matter, broken down, partly dis¬ 
solved, partly dissolving, and, it may be, partly 
undissolved. 

(2) Fatty matter, broken down, but not dis¬ 
solved. 

(3) Starch, being slowly converted into sugar, 
and as fast as it becomes sugar, dissolving in the 
fluids of the mixture. 

(4) Gastric juice, mixed with substances 1, 2, 3, 
and liquids, and such portions of aliment as are 
undigestible. 

Chief Functions of the Stomach: (1) To mix all 
food into a pulp; (2) To dissolve the nitrogenous 


212 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

portion of the food by means of the gastric juice. 
The conversion of starch into sugar, which takes 
place in the mouth, is in the stomach discontinued 
temporarily, but not suspended, as will be seen 
further on. 

Conditions Favorable to Stomach Digestion .— The 
following are among the most important: 1. A 
temperature of 100° F., nearly. Any reduction, 
such as results from overdoses of water or ice 
cream, may lead to serious results. When a sub¬ 
stance, instead of being digested in the stomach, is 
digested in the intestines, the time required is vastly 
greater. 

2. Continual motion of the walls of the stomach 
to permeate the food with gastric juice. 

3. The removal of such portions of the food as 
are thoroughly digested. This brings the remainder 
into better contact with the gastric fluid. 

4. Perfect mastication and insalivation of the ali¬ 
ment previous to its entrance into the stomach. 

5. A moderate quantity of food. The stomach 
should not be distended. 

6. Regular intervals between any two consecutive 
meals. They should be long enough for the food of 
one meal to have left the stomach before the next is 
introduced. 


THE DIGESTIVE SYSTEM. 


213 


7. No severe physical or mental exertion either 
immediately before or after a meal. 

8. A tranquil mind. 

9. Bodily health. 

10. Favorable weather. 

The Intestines furnish the fifth step in the course 
of digestion. When the food, digested and undi¬ 
gested, under the name of chyme passes the pylorus 
it enters the duodenum to undergo another change. 
About three inches from the entrance to this intestine 
a new digestive fluid reaches the food by a small 
duct. It is formed of two fluids, the bile from the 
liver and the pancreatic juice from the pancreas. 

The Bile is a greenish-yellow, very bitter alka¬ 
line liquid with a peculiar smell, secreted by the 
liver ( L , Fig. 38). The liver (1) secretes bile, and 
(2) modifies sugar for purposes which this has to 
serve. Bile contains waste materials which it has 
taken from the blood; it must, therefore, be con¬ 
ducted out of the system. If prevented from enter¬ 
ing the duodenum, it congregates in the blood, pro¬ 
ducing jaundice, and acting then as a poison. Should 
some of it happen to be thrown into the stomach, 
digestion there would cease at once; nausea and 
vomiting, the usual bilious symptoms, would occur. 


I 


214 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

It acts also as a solvent of the fatty portions of food, 
and as a stimulant to the action of the intestines. 
Chyme, after its union with bile and the pancreatic 
juice, is usually called chyle . The process being 
called chylification . 

The Pancreatic Juice is a clear, colorless liquid, 
distinguished (1) by its great capacity for digesting 
fats after they have become fluid by the warmth of 
the stomach; (2) by its dissolving albuminous sub¬ 
stances. It is secreted at the rate of six ounces a 
day by the pancreas, P, an organ about seven 
inches long, having the form of a bunch of grapes, 
and generally resembling the salivary glands of 
the mouth. This juice also enters the duodenum. 
It has three ferments; pancreatin , which changes 
starch into sugar; trypsin , which dissolves the 
remaining albuminoids, and a third which partially 
acidifies the fats, and which has not yet been 
named. The salivary glands and the pancreas are 
readily influenced by the nervous system; thus, the 
sight, or smell, or the mere thought of food may 
prompt the salivary glands to pour saliva into the 
mouth, or, in common language, cause “ the mouth 
to water.’’ 

The Intestinal Juice , a thin fluid, is secreted from 
minute glands on the interior surface of the small 


THE DIGESTIVE SYSTEM. 


215 


intestine; its business seems to be to digest albu¬ 
minous matter which has escaped the action of the 
gastric juice. The main office of the small intestine 
is to digest fat and to complete digestion by finishing 
the action of all previous fluids. Intestinal juice is 
also secreted from the colon. With the final action 
of the intestinal juice digestion is completed while 
absorption and assimilation begin in order to make 
the food a part of the blood. 

The quantity of these five liquids generated daily 
has been estimated at 22 pounds, nearly, of which 
that of the gastric juice amounts to about 15 
pounds. It is plain that their office is to dissolve 
the food and act chemically upon it. Each of them 
seems to have its special function, and yet none is 
exclusively directed to one object. They all aid 
one another, and are in turn assisted by the peristal¬ 
tic motion of the intestines, which thoroughly mixes 
the food with them, and propels the chyle from 
above downward through that portion of the alimen¬ 
tary tube which succeeds the stomach. The undi¬ 
gested masses collect in the rectum to be properly 
removed. 

Absorption and Assimilation. — Chyme and 
Chyle are merely digested food. Both are in the 
alimentary tube; one is in the stomach, the other 


216 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

in the intestines. As yet they are strangers to the 
system — that is to say, they do not form part 
of it. 

The oxygen of the air which enters the lungs 
rapidly burns up the particles of waste tissue which 
are thrown into the lungs by the venous blood. 
Now, this waste matter must be replaced by fresh 
particles, else the vital processes speedily cease. In 
other words, at every instant of life a quantity of 
animal tissue is dying, and must at the next instant 
be replaced. If no freshly-digested food is at hand, 
as during disease, the burnt up particles of the body 
are replaced, first, by the fat of the tissues, and 
hence the sunken appearance of the eyes and 
cheeks; or next, by the flesh of the tissues them¬ 
selves, which results in emaciation, and finally in 
death, unless a cure can be effected. Thus, death 
and life are intimately associated and dependent 
upon each other in the living organism. 

The question now arises: How is the digested 
aliment converted into blood so as to be distributed 
in this form over the entire body and to replace 
waste matter — in fact, to furnish the material 
for the growth and maintenance of the body? The 
answer is: The chyle throughout the course of the 
alimentary canal is taken up by capillaries and 
special minute vessels, called chyle-vessels or lac- 


THE DIGESTIVE SYSTEM. 


217 


teals, and conveyed into the circulation at large. 
With the aid of respiration, it is then made into 
nourishing blood. The process of taking up the 
chyle forms part of the process of absorption. 

Absorption. — The object of this process is, (1) to 
supply the blood with fresh materials; (2) to re¬ 
move such particles as have accomplished their 
mission in the body. Absorption, then, has a two¬ 
fold character; it absorbs essentials from without 
the bodies and carries them to the blood; it absorbs 
waste materials from within the system and conveys 
them outside the body. Absorption is mainly 
carried on by two distinct sets of vessels, viz., blood¬ 
vessels , or capillaries, and lacteals , or lymphatics, 
also called absorbents. The former are abundantly 
spread over the interior surface of the stomach, and 
both the small and large intestines; the latter only 
in the intestinal canal, but most numerously in the 
small intestine. Both sets of vessels form a perfect 
net-work, completely covering the interior surface of 
the intestinal canal; in the small intestine this net¬ 
work is closer to the chyle than anywhere else. 

Absorption by Blood- Vessels .— The minute blood¬ 
vessels and capillaries in the mucous coat of the 
stomach and intestines (Fig. 47) absorb at b and c 


218 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

completely digested aliment; this substance is so 
finely divided as to readily pass through the walls 
of the blood-vessels in the manner, roughly speak¬ 
ing, of water passing through (from without to the 
interior of) the walls of a hollow tube made of blot- 



FIG. 47 . 

TRANSVERSE SECTION OF MUCOUS MEMBRANE OF COLON. 

A, Artery. F, Vein, a a , Descending Veins, b b, Venous Net on 
Inner Surface, c, Capillaries in Mucous Membrane. 

ting paper. The blood at A is arterial; on its passage 
through the capillaries, h and c, it absorbs chyle 
(together with waste materials), which renders it 
venous; through a it descends into vein V, to be ulti¬ 
mately conveyed to the lungs. The blood-vessels are 
not very particular in the choice of fluid particles; 
they absorb nearly all kinds except the fatty portions. 






THE DIGESTIVE SYSTEM. 


219 


Water, and similar beverages, are believed to be 
absorbed by the blood-vessels of the stomach without 
passing into the duodenum. 



Fra 48. 

TRANSVERSE SECTION OF THE DUODENUM OF A CALF. 

1, Villi. 2, Interior Chyle-Vessels. 8, Glands. 4, Exterior Chyle- 
Vessels or Lacteals. 5, 6, Muscular Coat. * Valvular 
Chyle-Duct. 7, Skin. 











220 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Absorption by the Lacteals is carried on in the 
same manner. It is rendered most effective in the 
small intestine, because the interior wall of this intes¬ 
tine presents a larger surface to the chyle as it passes 
by. This greater extent of surface is owing to the 
fact that the mucous membrane which forms the in¬ 
terior surface, is folded into a great abundance of 
conical projections, called villi (Fig. 48), some¬ 
what resembling the velvety projections of a Turk¬ 
ish towel. From the villi the absorbed materials 
pass through the interior chyle vessels, 2, and 
through glands, 3, to the exterior chyle vessels, or 
lacteals, 4. These vessels gradually increase in size, 
and on leaving the intestine obtain the valvular 
structure of veins. This prevents any absorbed chyle 
from flowing back to the villi. The way in which 
each villus imbibes the chyle is explained thus : The 
villi have minute muscles which cause them alter¬ 
nately to contract and expand; at every expansion 
each villus fills with chyle; at every contraction 
it squeezes its contents into the lacteal vessels 
beyond. The villi may be compared to the delicate 
root-fibres of plants, which are spread in the ground 
for the purpose of absorbing food for the plant; like 
the villi, these vegetable fibres are without openings, 
and yet, as is known from the fact that drooping 
leaves revive again after a shower on a hot day, they 


THE DIGESTIVE SYSTEM. 


221 


are capable of absorption. The special function of 
the villi seems to be the absorption of the fatty por¬ 
tion of the chyle, although they absorb also other 
materials. The villi are found only in the small 
intestine. 

The lacleals receive the chyle from the villi of 
the intestines (Fig. 48, *) mentioned above. The 
lymphatic glands (p. 132, Fig. 28) which are widely 
distributed in the body are found among the lacteals 
described on p. 132. The chyle on passing through 
them undergoes some change, and on leaving them 
it flows into the thoracic duct. 

The thoracic duct (Fig. 45) is a tube of the width 
of a goose quill, nearly, which receives the chyle of 
the lacteal vessels and glands, and empties it 
into a vein on the left side of the chest, near the 
heart. A similar, smaller tube, likewise throws its 
contents into a vein on the right side of the chest, 
near the heart. Thus, the lacteal vessels are the 
carriers of the chyle on its way to the blood; they 
act like veins in this, that they contain valves to 
make their contents flow in one direction only; 
with one end they terminate in two ducts, which 
open into the large veins and finally into the heart; 
at the other end they terminate in microscopic 


222 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 



branches or lymph-capillaries, which are distributed 
throughout the tissues of the body. The villi form 

part of these lymph- 
capillaries. The lym¬ 
phatic vessels of the in¬ 
testinal canal pass by 
the name of lacteals , be¬ 
cause their contents 
resemble milk in appear¬ 
ance; there is no differ¬ 
ence between lacteals and 
lymphatics. It should 
be borne in mind that 
there are blood-vessels 
and capillaries within 
each villus as well as 
around the villi, which, 
as before mentioned, 
carry on absorption. 

From the preceding it 
is evident that man and 
the higher vertebrates 
FIG . 49 . have, in addition to the 

The Thoracic Duct. intricate system of arte¬ 

ries and veins, another 
of vessels, called the lymphatic system. (See p. 
132). This contains a fluid called lymph , which 





THE DIGESTIVE SYSTEM. 


223 


system is chyle altered by the lymphatic glands. 
As the blood-vessels have blood capillaries, so the 
lymphatic-vessels have lymph-capillaries near the 
skin; these widen into lymph-vessels toward the 
interior of the body. 

5. FOOD. 

The Subject of Food will be considered under four 
heads: (1) Necessity for Food; (2) Sources and 
Classes of Food ; (3) Quantity and Quality of Food; 
(4) How and When Food Should be Taken. 

(1) The Necessity for Food will be the first to be 
discussed: — 

The Functions of the Human System cause a waste 
of tissues. This waste must be repaired or the in¬ 
dividual will die. The human body is composed of 
combinations of carbon, hydrogen, oxygen, and 
nitrogen; hence it must be repaired by a supply 
of aliments containing these materials. When an 
organism is deprived of proper food it commences 
to feed upon itself. 

Waste of Tissue arises from the incessant work 
which the body performs, consisting of mechanical 
motion, as when a person is walking, or a blacksmith 


224 ANATOMY, PHYSIOLOGY, AND HYGIENE 


strikes a piece of iron on the anvil; or of vital func¬ 
tions, such as breathing. Not only is food required to 
supply the waste of tissue as well as to build up the 
organism at the beginning; but the temperature 
of the body must be maintained, for which the 
oxygen is so necessary. Hence, there may be three 
distinct offices of food: (1) To build up the being 
at the beginning; (2) To supply the waste after its 
growth is attained; (3) To maintain the normal 
temperature of the body; to appear hungry may be 
added as a secondary purpose of food. 

Hunger and Thirst .*—The man whom we sup- 


* “ We none of U3 object to a sharp-set appetite; that is by no 
means unpleasant, especially when there is food at hand; but if 
this is not the case, it soon becomes a craving passion — a 

strong impelling power. The cravings of hunger have done 

much for this world; ‘look where we may, we see it as the 
motive power which sets the vast array of human machinery in 
action.’ Hunger is also the incentive which directs our atten¬ 
tion to the system’s need for food, and if it be sharp enough the 
most loathsome substances are greedily devoured. By it has 
man, and civilized man, too, been driven to feed upon the putrid 
corpse of his comrade. Hunger is one of the great forces in 

action in the preservation of the life of the individual; and the 

fear of it is one of the strongest incentives to action. But the 
pangs of hunger are tolerable in comparison with the tortures of 
raging thirst. In fact, so terrible are the latter that they form 
one of the crudest tortures which man can inflict on man; so 



THE DIGESTIVE SYSTEM. 


225 


posed to take exercise in a glass-house would dwin¬ 
dle to nothing in due course of time unless he took 
food to repair his waste. The imperious sensations 
which remind us forcibly of the want of solid and 
liquid aliment are hunger and thirst. To satisfy 
the former, the body must be supplied with solid 
food; to satisfy the latter, with water in some shape 
or other. 

The sensation of hunger seems to be seated in the 
stomach, but it is the call for food of the whole 
system; for when food enters the system by any 
other source, the sensation will disappear. 

So it is with the sensation of thirst, which appears 
to be in the throat, but is really the cry of the entire 
body for water. 

(2) The Sources and Classes of Foods deserve 
most careful attention, as the character of the food 
often determines the nature of the being. The fol¬ 
lowing experiments show something of the nature and 
properties of the four chief elements of food: — 

Experiment. — Hydrogen gas may be liberated 
from muriatic acid poured on a little zinc or on a nail 

cruel a torture, indeed, that it has rarely been used, except in 
cases of bitter personal animosity, by others than brutal Eastern 
tyrants, or bigots under the influence of religious fanaticism.”— 
Fothergill on the Maintenance of Health. 

15 



226 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

in a test-tube. The gas is recognized by its burning 
with a pale, bluish flame. By connecting the mouth 
of the test-tube with a suitable tube, the gas may be 
conducted into a tumbler filled with and inverted 
over water. 

Experiment. — Oxygen gas may be liberated 
from an ounce of pulverized potassium-chlorate 
mixed with a like quantity of manganese dioxide, by 
placing the mixture in a test-tube and applying heat. 
It may be recognized by its rekindling a glowing 
taper; like hydrogen, it is easily caught in an in¬ 
verted tumbler. 

Experiment. — Nitrogen gas may be obtained 
from common air by burning a short piece of candle, 
fastened on a fragment of board so as to float on 
water, and inverting a glass jar over the candle. 
The light will be extinguished, some water will rise 
into the jar, and nearly all the remaining gas will be 
nitrogen. 

Carbon may bo represented by a piece of coke or 
charcoal. 

Hydrogen , Oxygen , Nitrogen — three gases — and 
carbon —a solid — are the principal elementary sub- 


THE DIGESTIVE SYSTEM. 


227 


stances which, when combined with each other, form 
the materials composing the human body. 

It is divided into organic and inorganic materials. 
(See p. 3.) 

The following outline shows the classes of 
foods:— 


Food. 


* I. Organic 


1. Nitrogenous sub¬ 
stances, or 
Albuminoids.... 

■ 2. Oleaginous Sub¬ 
stances. 

3. Saccharine Sub¬ 
stances. 


f a. Albumen, 
i b. Fibrine and 
Gluten. 

[ c. Caseine. 
f Oils. 

1 Fats, 
f Starch. 

■j Sugar. 

I Gum. 


f Water. 

j Salt (common), 
j Lime. 

I I Iron. 

I II. Inorganic. •! 

Oxygen. 

I Soda. 

Potash. 
Magnesia, etc. 


The last two classes, when pure, contain no nitro¬ 
gen. Inorganic food comprises water, the most im¬ 
portant article of food, and alkalies, such as salt and 
phosphates. No single class is generally considered 
sufficient; all of them are necessary to make food 
nutritive and convenient; a man feeding entirely 
upon bread and sugar may ultimately be starved as 
surely as one whose diet is composed solely of meat, 







228 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

or of mineral water. Intuitively, we eat bread and 
meat, or bread and cheese, bacon and beans, stuffing 
and fowl. Persons who live largely on meat prefer 
it fat; those who live mostly on vegetables consume 
a great deal of milk, because milk contains the 
three classes of organic food, as well as inorganic 
materials. 

Oxygen is an article of food, as it serves to main¬ 
tain important vital functions. It is the only article 
of food which enters the system as a simple, or 
elementary body; all the others are compounds. 

Organic Foods form the chief supply of aliment 
for the animal body, and the principal of these is the 
nitrogenous substances, which Liebig calls the flesh- 
formers , as he denominates the second and the third 
divisions as the force-producers, or carbonaceous 
foods. 

Albumen is found in meat, grain, milk, and juices 
of plants, but the whites of eggs furnish it in the 
purest state. Albumen forms the greater part of 
brain tissue. It is colorless, tasteless, and without 
smell, and coagulates with heat, acids, and alcohol. 

Fibrinc is found in forming the basis of the mus¬ 
cles, the blood, lymph, and chyle. It is white, 
ordorless, and insoluble in cold water. It coagu- 


THE DIGESTIVE SYSTEM. 229 

lates at all temperatures. Gluten is vegetable 
fibrine. 

Caseine is the curd-like ingredient in milk. It 
coagulates by the presence of acid, produced by 
fermentation, when the caseine may be separated 
from the watery part of the milk, termed whey . 

The Oleaginous Substances form the second class 
of organic food substances. These belong with the 
sugar, etc., to Liebig’s “ force-producers.” They 
are insoluble in water, but are suspended in the fluids 
of the body in finely divided state. Although both 
animals and plants supply oleaginous substances, the 
former furnish the greater amount for man’s food. 

The Starches, Sugars, and Gums constitute the 
third and last division of organic food substances. 
Starches and gums are of about the same nature as 
sugars, being composed of nearly the same proportion 
of elements and serving the same purpose in the ani¬ 
mal economy. Most sugars are derived from plants, 
milk and honey furnishing the only supply from an 
animal origin. Sugar dissolves readily, has a sweet 
taste, with a tendency to ferment and crystallize. 


Starch, as a vegetable principle, is abundant. It 
is formed of minute bodies of regular structure. 


230 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


tasteless, without odor or crytallization, and dis¬ 
solving only in boiling water. Its uses as a food- 
supply are universal. 

Gum is similar to starch, but not so nutritious. 
It is in a better commercial form, and much used 
in the arts. 

The Inorganic Foods are few in number, yet 
they are very important. 

Water stands at the head of inorganic substances 
not only from its importance, but also from its 
abundance, as about three-fifths of the animal tissue 
is composed of water. It is found in all part3 of 
the body, even in the composition of the teeth, 
which contain one-tenth water. Fifty per cent of 
the muscle tissue is water. Vegetables and fruit 
are largely composed of water. When we think of 
its composition, two parts oxygen and one hydrogen, 
by bulk, we realize how necessary to the life of 
the being it is. 


Salt* is another chemical compound, composed of 


* “ Salt-cellars ever should stand at the head 
Of dishes, wheresoe’er a table’s spread. 
Salt will all poisons expurgate with haste, 



THE DIGESTIVE SYSTEM. 


231 


sodium and chlorine, which seems absolutely neces¬ 
sary to the healthfulness of animal bodies. It is 
present in nearly all plants and animal tissue, but is 
found and native, in solution in water in the mineral 
kingdom. 

Without salt, animals cannot thrive. Their food 
is not properly digested, their skin becomes dry 
and rough, the hair falls out, and unless salt is 
secured, death will result. Salt as a medicine has 
many fine qualities known to every housewife. 

Iron is necessary to the healthful state of the 
system, especially the muscles and the blood. In 
the blood, it forms one-tenth per cent of the sub¬ 
stance. Iron seems to give color and vitality to 
the blood, being found in its red corpuscles. 

Lime (calcium and oxygen ) is the chief ingredi¬ 
ent of the bones, where it is combined with phos¬ 
phoric acid and carbon dioxide. Lime is found in 

And to insipid things impart a taste. 

The richest food will be in great default 
Of taste, without a pinch of sav’ry salt. 

Yet of salt meats, the long-protracted use 
Will both our sight and manhood, too, reduce; 

On tables salt should stand both first and last, 

Since, in its absence, there is no repast.” 

— The Code of the School of Salemum. 



232 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

meat, milk, and the grains. It is necessary to the 
growing body, which would be subjected to serious 
consequences heretofore discussed on page 18. 

Magnesia, found in the bones, brain, milk, etc. 

Potash and Soda, found in the blood, bile, per¬ 
spiration, milk, etc. 

Phosphorus of the bones and Sulphur in the 
hair, muscles, bones, and nails, with some of the 
elements mentioned before, conclude the review of 
inorganic food substances, although a few others 
might be named. 

(3) The Quantity and Quality of Food constitute 
the next topic of the subject, both of which exert 
a wide influence upon the welfare of man. 

The Quantity and Quality of Food Depend 
Upon —(a) the health, (b) the climate, (c) the 
occupation, (d) the age, (e) the sex, and (f) the 
kind of food. 

The Health of the body certainly determines to a 
great degree the supply of food required, for in 
sickness the organs are “out of tune,” at which 


THE DIGESTIVE SYSTEM, 


233 


time food is repelled. In good health, the stomach 
labors under too heavy a load, which admonishes 
one to guard the health. In some diseases, as dys¬ 
pepsia for example, the stomach will take but little 
aliment, and that which is accepted produces excru¬ 
ciating pain. Not only must the quantity be modi¬ 
fied in sickness, but also its quality and nature. 
Again, persons of spare form should make their diet 
largely of fats, starches, and sugars, while those 
whose plumpness offends the eyes should reject the 
foregoing regimen, and live more upon vegetables 
and less upon meats. Invalids, persons of weak con¬ 
stitution, and infants should not only eat sparingly, 
but their food should be of a light, nutritious nature. 
Gruels, broths, rice, vegetables, and light meats 
should make up the diet of such persons. 

Little or no food will be required immediately after 
severe mental labor, continued singing and speaking, 
or laborious manual toil. Then the digestive system 
needs rest, not food. 

Climate is an important factor in determining the 
quantity and quality of food. Every one knows the 
well-known facts, that the Esquimo subsists upon 
whale blubber and oil, taken in large quantities, but 
the inhabitant of the tropics lives almost entirely upon 
fruits, while the native of the temperate zone, who 


234 


ANATOMY, PHYSIOLOGY, AND HYGIENE, 


is cosmopolitan in his tastes and requirements, levies 
for his food supplies upon the animal, mineral, and 
vegetable kingdoms of all climes. 

One of the Arctic explorers speaks of an Esquimo 
who, after eating a hearty breakfast, came on board 
the ship, and ate twenty-four pounds of rice —a deli¬ 
cacy to him. It was no unusual thing for one of these 
odd people to eat a whole sheep at one sitting, or for 
two or three of them to eat the hind-quarters of an 
ox. In contrast to this is the light diet, in quantity 
and quality, customary among the people near the 
Equator. 

Yet, the inhabitant of the temperate zone shows his 
superiority here, as well as in the field of intellect, 
and it has been determined that a mixed diet * is best 

* “ The mixed diet to which the inclination of man in temperate 
climates seems usually to lead him, when circumstances allow 
that inclination to develop itself freely appears to be fully con¬ 
formable to the construction of his dental and digestive apparatus, 
as well as to his instinctive cravings. And whilst on the one hand 
it may be freely conceded to the advocates of ‘ vegetarianism,’ that 
a well-selected vegetable diet is capable of producing, in the 
greatest number of individuals, the highest physical development 
of which they are capable, it may, on the other hand, be affirmed 
with equal certainty, that the substitution of a moderate propor¬ 
tion of animal flesh is in no way injurious; but, so far as our 
evidence at present extends, this seems rather to favor the highest 
mental development. And we can scarcely avoid the conclusion 
that the Creator, by conferring on man a remarkable range of 



THE DIGESTIVE SYSTEM. 


235 


for man’s highest development, physically, mentally, 
and morally; because no single article of diet con¬ 
tains all the elements required. 

The Occupation (see table, page 254,) Followed, 
like the kind of exercise taken, affects the quantity 
and quality of the daily food supply. A person 
whose trade, business, or profession requires little or 
no exertion should regulate his diet accordingly, eat¬ 
ing sparingly of meats and heavy foods ; but, on the 
other hand, the laborer who from morning until even¬ 
ing, constantly uses shovel and pick, lifting heavy 
loads at the expense of muscular tissue, must have 
plenty of solid, wholesome, nutritious, force-produc¬ 
ing food to supply this great waste. No meager diet 
will sustain him, which has been proven in the unfor¬ 
tunate cases of criminals put to hard labor without 
food in proper quantity and the right quality. Those 
occupations, requiring much time in the open air, su¬ 
perinduce a better condition of the digestive system, 
and make more food necessary. 

Sex is to be considered under this head. Females, 
other conditions being equal, eat less than males. 

choice, intended to qualify him for subsisting on those articles of 
diet, whether animal or vegetable, which he finds most suitable to 
his tastes and wants.”— W. B. Carpenter on the Principles of 
Physiology. 



236 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

When the general nature and occupations of the two 
sexes are considered, this will be readily accounted for. 

Age* serves notice of its varying demands upon 
the supply of food. In infancy the supply is simple 
and of a liquid nature, milk furnishing the ideal 
material at this period. It is interesting to know that 
milk also was the primitive food of the race. In 
youth, when the building-up process is so active, 
food must be abundant and taken often as the system 
demands, while in old age, as the “ machine begins 
to run more slowly,” the fuel is less and of not so 
heavy a nature. Hence, there is a reason for the 


* Here is an interesting table showing the results of occupation 
upon longevity. It is worthy of thoughtful study: — 


Employment. Years. 

Employment. Years. 

Judges.65 

Farmers.64 

Bank Officers. 64 

Coopers.58 

Public Officers.57 

Clergymen.56 

Masons.48 

Traders.46 

Tailors.44 

Jewelers.44 

Manufacturers.43 

Rakers T .43 

Shipwrights.55 

Hatters.54 

Lawyers.54 

Rope Makers.54 

Blacksmiths.51 

Merchants.51 

Calico Printers.51 

Physicians.51 

Butchers...50 

Painters.43 

Shoemakers.43 

Mechanics.43 

Editors.40 

Musicians. 39 

Printers.38 

Machinists.36 

Teachers.34 

Clerks . 34 

Carpenters.49 

Operatives.32 










































THE DIGESTIVE SYSTEM 


237 


strong appetite of the vigorous youth as compared 
with the reasonable, quiet demands of old age. 

An infant requires absolutely less food than an adult, 
but relatively to their weights a much larger amount. 

Tlie Kinds of Food,* having been so fully dis¬ 
cussed elsewhere, need but little attention here. As 


* DIGESTIBILITY OF FOODS. 


Article op Food. 

Condition. 

Hours 

Required. 

1 

ApwTicleof Food. 

Condition. 

Hours 

Required. 

Hicc . 

Boiled. 

1 00 

f 

Sonp beans. 

Boiled. 

3 CO 

Kggs, whipped. . 

Raw. 

1 30 

[Soup, Chie,ken .... 

it 

3 00 

Trout, salmon, fresh 

Boiled. 

1 30 

Apple dumpling.... 

it 

3 00 

Apple's, sweet and 



Fresh oysters..7.... 

Roasted ... 

3 15 

mellow. 

Raw . 

1 30 

iPork steak . 

Broiled... 

3 15 

Venison steak. 

Broiled. 

I 35 

| Fresh mutton. 

Roasted .... 

3 15 

Tapioca . 

Boiled. 

2 00 

ICorn bread. 

Baked.. 

3 15 

Harley. 

it 

2 00 

1 Carrots. . 

Boiled. 

3 15 

Milk.!. 


2 00 

iFresh sausage. 

Broiled. 

3 20 

Bnllor.k’s liver,fr’sh 

Broiled. 

2 00 

!Fresh flounder. 

Fried. 

3 30 

Fresh eggs. 

Raw. 

2 00 

;Fresh catfish. 

4 <5 

3 30 

Codfish, r.nred and 



Fresh oysters. 

Stewed. 

3 30 

dry. . 

Boiled. 

2 00 

Butter.!.«. 

Melted. 

3 30 

Milk 

Raw. 

2 15 

Old strong cheese.. 

Raw. 

3 30 

Wild turkey. . 

Roasted. 

2 15 

Mutton soup. 

Boiled. 

3 30 

Domesticturkey ... 

it 

2 30 

Oyster soup. 

it 

3 30 

(inoae. 

it 

? 30 

iFresh wheat bread.. 

Baked . 

3 30 

Sncklngpig. 

a 

2 30 

iFlat turnips. 

Boiled. 

3 30 

Fresh lamb. 

Broiled.. 

2 30 

Irish potatoes. 

it 

3 30 

Hash, meat and 



Fresh eggs. 

Hard boiled 

3 30 

Vegetables. . 

Warmed..... 

2 30 

it it 

Fried. 

3 30 

Beans and pod. 

Boiled. 

2 30 

Green corn and 



Parsnips 

it 

> 30 

beans... 

Boiled. 


Irish potatoes. 

Roasted 

2 30 

Beets. 

a 

3 45 

Ohieken 

Fricassee.... 

2 45 

Fresh lean beef. 

Fried. 

4 00 

Custard 

Bilked. 

2 45 

Fresh veal. 

Broiled. 

4 00 

Salt Beef. 

Boiled_ 

2 45 

Domestic fowls. ... 

Roasted.... 

4 00 

Sour and hard np* 



Ducks . 

it 

4 00 

pies. . 

Raw. 

2 50 

Beef soup, vegeta- 



Fresh oysters. 

a 

> 

bles ami bread 

Boiled. 

4 00 

Fresh eggs 

Soft boiled. 

3 00 

Pork,recently suited 

it 

4 30 

Rppf fresh, lpfln find 



Fresh veal 

Fried. 

4 30 

i a r«... 

Roasted.... 

3 00 

Cabbage with vine- 



Reef steak 

Broiled. 

3 0O 

gar.— ... 

Boiled. 

4 30 

Pork,recently salted 

Stewed. 

3 00 

jPork, fat and lean.. 

Roasted_ 

5 30 

Frebh mutton. 

Boiled __ 

3 00 

1 


























































































































238 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

to what a person should eat or should not eat is 
a matter he should settle for himself. Experience 
shows that those who think little and say less about 
what they ought to eat, but who eat at the proper 
times and in the proper quantities, may take almost 
anything with impunity. Quantity kills oftener than 
kind. The person of reasonably good digestion may 
eat any kind of food he chooses, provided it is thor¬ 
oughly masticated. Yet that which is most easily 
digested is not always best, as it may pass through 
the system too rapidly. Starch, arrowroot, sago and 
tapioca contain no nitrogen, and would not long sus¬ 
tain the vital functions. The careful perusal of the 
preceding pages and the study of the table below will 
suggest what ought to be one’s diet. 

Below is appended an interesting and useful table 
of an ideal daily diet, by Augustus D. Waller, which 
he divides into foundation and accessories . 


f 1 pound bread, 




1 $ pint milk, 
k pound eggs, 

^ £ pound cheese, 


(4) How and When Food Should he Taken is 
the fourth and not the least important of these topics. 


THE DIGESTIVE SYSTEM. 


239 


The Condition of Food when taken into the sys¬ 
tem is an all-important matter. The experience of 
civilized man leads to the conclusion that food for his 
use should be cooked. Cooking, or rather proper 
cooking, is a problem that receives too little attention 
in these days. What mischief may result from an 
improperly cooked piece of meat or what danger may 
lie in a pudding, tempting to the taste, yet fatal to 
the stomach,* are questions of more than ordinary 
interest, and deserve more than a passing notice. 
Years are spent in learning to perform indifferently 
upon a musical instrument, while the time spent to 
supply the proper material for the most perfect of all 
instruments — the human body—is meager and beg¬ 
garly. Let the women of the land work a social 
revolution upon the subject of cooking. 


* The stomach is the mainspring of our system; if it be not 
sufficiently wound up to warm and support the circulation, the 
whole business of life, in proportion, is ineffectually performed; 
we can neither think with precision, walk with vigor, sit with 
comfort, nor sleep with tranquility. There would be no diffi¬ 
culty in proving that it influences, much more than people 
imagine, all our actions.'’ 

“The fact is, that by skillful manipulation the plainest fare 
may be transformed into dishes fit for kings; while by ignorance 
and inattention, the best viands may be rendered unfit for human 
food. Dyspepsia is a fearful foe to the human race.”— The House¬ 
wife's Library . 



240 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

The Time at Which Food Should be Taken 
depends upon many things. 

Should the body be tired from vigorous exercise or 
heavy work , or in a heated condition , food should not 
be eaten until the individual is partially rested and 

While eating do not drink too much , as the saliva 
will not flow so freely under these conditions, and then 
the stomach is more apt to be overloaded. Yet, 
fluids may be used at meals, if used in the proper 
manner and quantity. 

An old saying: Never go to bed on a full stomach , 
may be supplemented by never going to bed on an 
empty stomach .* 


* “ It is a common impression that to take food immediately 
before going to bed and to sleep is unwise. Such a suggestion is 
answered by a reminder that the instinct of animals prompts them 
to sleep as soon as they have eaten; and in summer an after-dinner 
nap, especially when that meal is taken at mid-day, is a luxury 
indulged in by many. If the ordinary hour of the meal is 6 or 7 
o’clock, and of the first morning meal 7 or 8 o’clock, an interval of 
twelve hours, or more, elapses without food, and, for persons 
whose nutrition is at fault, this is altogether too long a period of 
fasting. That such an interval without food is permitted, explains 
many a restless night, and much of the head and backache, and the 
languid, half-rested condition on rising, which is accompanied by 
no appetite for breakfast. This meal itself often dissipates these 
sensations. It is, therefore, desirable, if not essential, when in¬ 
creased nutriment is needed, that the last thing before going to 
bed should be the taking of food. Sleeplessness is sometimes 



THE DIGESTIVE SYSTEM. 


241 


6. HYGIENE AND DISORDERS. 

HYGIENE OF THE DIGESTIVE SYSTEM. 

Under the heading, “ How and when Food should 
he Taken,’’ much has been said that would apply to 
the present topic; however, some additional remarks 
in a general way will not be out of place at this 
point. 

It might be laid down as a general law, that the 
organs do one thing at a time; hence, when one set 
of organs is laboring at one thing, another duty can 
not be done and be well done. In work, mental or 
physical, the muscular and mental powers of the 
body are employed, and the stomach should have 
rest. During, and for a time after meals, the 
stomach is at work, at which time the physical and 
mental powers should rest. The blood, like a trusty 
servant, hastens to the place where its master needs 
it. During digestion it waits upon that system; 
while physical employment or exercise is going on 


caused by starvation, and a tumbler of milk, if drunk in the middle 
of the night, will often put people to sleep when hypnotics would 
fail of their purpose. Food, on rising, is equally important and 
expedient. It supplies strength for prolonged bathing and dress¬ 
ing, laborious and wearisome tasks for the underfed, and is a bet¬ 
ter morning * pick-me-up ’ than any other of the too often resorted 
to ‘ tonics.’ ”— B. M. Hodges. 


16 



242 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

it is with the muscles, and finally when the brain 
labors, there this trusty servant will be found, at 
all of which times it leaves the other portions of the 
system not well attended. 

How much food must be taken is a question that 
comes to each one. As a precept that will be of 
great service follow this : — 

Stop eating before your appetite is fully satisfied. 
It is difficult to do this, but it can be done if the 
will rules the stomach , but if the stomach rules the 
will , there’s danger. 

Food should not be taken immediately following 
close mental application , long-continued speaking or 
singing , as the digestive system needs a little re¬ 
cuperation. This accounts for the listless way in 
which teachers or clerks will sit down to their meals 
when a cheerful, lively spirit ought to prevail. 

Sad or unexpected news will unfit the individual 
for taking food. Under this head, attention is 
called to the reprehensible habit of discussing un¬ 
pleasant, disagreeable, or harrowing subjects at the 
table. On the contrary, light, pleasant, humorous 
conversation should prevail during the meal time. 

Meals should be eaten regularly , as the bodily 
organism will form this habit, and it is a good one. 


THE DIGESTIVE SYSTEM. 


243 


Should the time of meals be postponed, overeating 
may be the result. Again, after the natural desires 
of food — hunger — has subsided one may not care 
much for nourishment, hence, careless habits and 
evil effects will follow. 

Use condiments very sparingly , as the cessation 
of appetite is notice that the stomach needs less 
food. There is no appetizer better than the 
thorough mastication of the food, 

DISORDERS OF THE DIGESTIVE SYSTEM. 

Among the most common disorders of the digestive 
apparatus may be mentioned the following: Dyspep¬ 
sia, Acidity of the Stomach , Colic , Constipation , 
Diarrhea , Bilousness and Peritonitis ,. 

Dyspepsia is literally poor digestion, or as it is 
commonly termed, indigestion , which is a lack of tone 
and strength in the digestive apparatus. It may be 
inherited. Alcoholic drinks, drinking ice water at 
meals, imperfect mastication, overeating, and irregu¬ 
lar meals are fruitful causes of the disorder. 

Treatment. — First remove any or all of the above 
causes. Eat sparingly, and of fresh meats, oysters, 
eggs, fresh vegetables, rice, tapioca, oatmeal, fruits, 
using hot-water drinks with some mild tonic, as 
calumba. By proper care, dyspepsia, in its incipient 


244 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

stages, may be permanently cured. Lime water and 
milk is an excellent remedy. 

Acidity of the Stomach is heart-burn, water 
brash, belching of gas, etc., accompanied by a sallow 
complexion, painful digestion, and mental despond¬ 
ency, and caused by a derangement of the acids and 
alkalies of the alimentary canal. 

Treatment .— In general, too much alkali may be 
counteracted by daily taking a mineral acid, while the 
superabundance of acids may be overcome by doses 
of alkali. Certain waters, recommended by physi¬ 
cians, may be secured that will gradually cure this 
disorder. 

Colic has several forms, the most common being 
the one affecting the stomach, and caused by ex¬ 
posure, or eating indigestible and unwholesome food, 
followed by sudden and severe pains, which come and 
go at intervals. 

Treatment .— When due to something that has been 
eaten, administer an emetic, or a mild laxative. 
Unless one of the special forms, colic is unpleasant 
but not serious. 


THE DIGESTIVE SYSTEM. 


245 


Important Facts. — No system of the human 
body admits of more varying effects, from varying 
conditions and environment, than the digestive, 
whose field seems to be full of paradoxes. In tastes, 
appetites, powers of digestion, physiology, habit,— 
in fact, in all powers, peculiarities, and affinities, 
men differ as widely as they do in longevity, stature, 
and weight; hence it is difficult to deduce laws and 
principles from the results obtained in the study of 
this department of human physiology, yet a few 
general and specific facts will be interesting, if not 
useful. 

Certain articles of diet are prescribed, yet it is said 
that Pythagoras, the early Grecian philosopher, lived 
to a ripe old age upon bread and honey, while John 
the Baptist subsisted upon “ locusts and wild honey.” 
A reputable medical journal tells of a man in Central 
America, who lived to be 164 years old, who ate but 
one meal a day and that cold, who drank nothing but 
cold water, and whose skin was like parchment. 
The wonderful experiments of Dr. Beaumont upon 
Alexis St. Martin shows how “ God moves in a 
mysterious way his wonders to perform,”—when, 
by a serious accident to St. Martin, the mysteries of 


246 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

digestion have been recorded. Dr. Tanner, in our 
times, lived forty days without food. 

Man requires daily about six pounds of food, of 
which the mineral kingdom supplies three and a half 
pounds; the vegetable kingdom, one and one-half 
pounds, and the animal kingdom, one pound, all of 
which amount is about one twent}^-fifth of the body. 

The body renews itself according to good authori¬ 
ties about once in seven years. Of course this pro¬ 
cess of renewal and decay is going on at every 
moment of time. 

The great length of the alimentary canal is neces- 
ary that every particle of nutriment may be extracted 
by the numberless absorbents along the way. 


THE DIGESTIVE SYSTEM. 


247 


REVIEW QUESTIONS. 

1. Give Dr. Hunter’s views of the stomach. 

2. In what respect is the human body like a machine? What 
makes the body do its work? What the steam-engine? 

3. How does working depend upon food? How does 
thought? 

4. How does the food of plants differ from that cf animals? 

5. From what source is the chief supply of food for animals 
and plants? 

6. Name the changes, or processes that food undergoes in the 
body. 

7. What is the chief channel by which food enters the body? 
Name an exception. 

8. State the organs of digestion. What organ is classed here, 
although not strictly belonging to this classification? 

9. Describe the mouth. To what may it be compared? 

10. Tell what you know about the teeth, their structure, kinds, 
number, and uses. How do the teeth of carnivorous animals 
differ from those of herbivorous? Describe the pharynx. How 
many openings has it? 

11. Name the salivary glands. On which jaw are they? Which 
are affected in mumps? What is the frcenum linguae ? Where are 
the mucous glandules? To what may the salivary glands be 
likened? 

12. Locate and describe the oesophagus. 

13. Why is the stomach so important? What other organ is 
near it in size? Locate the stomach. Name and locate its two 
openings. Give and describe its three coats. What juice does it 
contain? Give its size, capacity, appearance, and rugse. 

14. Give the chief and subdivisions of the intestines. Give the 


248 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


length of each main division. In wliat respect are the intestines 
like the stomach? What is the alimentary canal? How long is 
it? Describe each part of the small intestine. Of the large. 

15. What is the meaning of the name of each part of the small 
and the large intestine? 

1G. What is the omentum? Give another name for it? How 
many coats has it? Its use? 

17. Describe the liver, giving its size, dimensions, location, 
composition, and uses. 

18. Where is the gall-cyst, or gall-bladder? Describe it. Give 
its uses. 

19. What is the description of the pancreas? In what respect 
is it like the liver? 

20. What is the use of the spleen? Describe this organ. How 
is it unlike the liver and pancreas? 

21. Describe fully the lacteals. What are the villi ? The 
mesentery ? Lymphatic glands? 

22. Tell what you know of the thoracic duct, as to location, size, 
structure, and uses. Into what vein does it empty its contents? 
How many coats have the lacteals and thoracic duct? 

23. Give a full description of the kidneys. With what organ do 
they connect? What is the peritoneum? 

' 24. Describe the process of mastication. Food undergoes what 

two changes in digestion? What is the use of the tongue in 
mastication? Which jaw is the more important? 

25. Explain insalivation. How is starch in plants changed to 
sugar? Why are mastication and insalivation so important? Sum 
up the uses of saliva. 

26. Follow out carefully the process of deglutition. What part 
does the tongue play here? What keeps the food from entering 
the windpipe? 

27. Tell what you know about the oesophagus regarding 
digestion. Give the manner of getting food down the gullet. 


the digestive system. 


249 


28. Describe the process of stomach digestion. What is the 
gastric juice? Which coat gives the physical action? What is the 
peristaltic motion? What is chyme? What muscles act in 
vomiting? Give the power of gastric juice. How does alcohol 
hurt the stomach? Give the different properties of gastric 
juice and their effects? What is albuminose? How many pounds 
of gastric juice are daily secreted? 

29. Give the condition of chyme, as it leaves the stomach. 
Name the chief functions of the stomach. 

30. State the conditions favorable to stomach digestion. 

31. Describe the digestion in the intestines. What are the 
properties and uses of the bile, of the pancreatic juice? What is 
the effect of bile, if not allowed to enter the duodenum? How 
does the nervous system affect the flow of digestive juices? What 
is chyle ? 

32. Describe the intestinal juice. Give its uses. Give the 
amount of these five juices daily secreted. 

33. Compare chyme and chyle. Why is food necessary? What 
vessels take the chyle from the intestines and transfer it to the 
thoracic duct? 

34. Describe the process of absorption by the blood-vessels. 
Absorption by the lacteals. What part do the villi play? What 
membrane holds the lacteals and lymphatic glands in place? 

35. Describe the process of digestion in the thoracic duct? 
What two systems of circulation has man? 

36. What causes waste of tissue? Give the example of the 
man in a glass-house. What are the relations of building-up and 
tearing-down processes in the different stages of life? Give the 
three uses of foods. 

37. Tell what you know of hunger and thirst. Define each. 

38. Name some of the elements that largely enter into our food 
supply. Show how each may be obtained. Give the relation of 
animal, mineral, and vegetable kingdoms. 


250 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


BLACKBOARD OUTLINE. 


VII. THE DIGESTIVE SYSTEM. 


r Human Body. 

1. Introdnotion. < Food of Plants. c Digestion. 

( Changes of Food by 1 Absorption and Assimilation. 
( Excretion. 


2. The Organs of Digestion (named below). 


3. Their Structure. 


a. The Mouth. 


i Organs of Mastication. 

) Organs of Taste. 

( Number. 

b. The Teeth. 1 Parts. 

C Structure. 

r 2 Parotids. > 

c. The Salivary Glands. < 2 Submaxillaries. > Ducts. 

( 2 Linguals. ) 

d. The Pharynx—Its Openings. 

e. The Oesophagus — Structure. 

f Location. r Coats. 

The Stomach j Structure.Openings. 

i tie stomach.< Gastr j c j n j ce . ^Dimensions. 


/• 


[Glands. 

fSmall, 


g. The Intestines 


'1 


Large. 


r Duct. 

h. The Liver. < Cells. 

( Juice. 

• i The Lacteals. 

*'* } The Thoracic Duct. 


Duodenum. 

| Jejunum. 
Ileum. 

Caecum. 

| Colon. 

Rectum. 

■ Gall-Cyst. 

Pancreas. 
i Spleen. 

The Kidneys, 
'lhe Omentum. 





4. The Process of Digest Jon — Through the Above Organs. 


5. Food. 


fl. Necessity for. 

J 2. Sources and Classes of. 

) 3. Quantity and Quality of. 

[4. IIow and When Food Should be Taken. 


6 . Hygiene and Disorders. 


a. Hygiene. 


b. Disorders. 


i Ru’es of. 

I Necessity of. 
f Dyspepsia. 

\ Acidity of the Stomaoh. 
1 Colic. 



VIII. 


THE NERVOUS SYSTEM. 


Then mark the cloven sphere that holds 
/Ill thought in its mysterious folds ; 

That feels sensation's faintest thrill, 

End flashes forth the sovereign will; 

Think on th 7 stormy world that dwells 
Looked in its dim and clustering cells I 
The lightning gleams of power it sheds 
Along its hollow, glassy threads 1 

— Holmes. 

( 251 ) 





THE CEREBRO-SPINAL SYSTEM. 


( 252 ) 


VIII. The Nervous System. 


X. INTRODUCTION. 

We have become acquainted with the various 
bones and tissues which compose the structure of 
the body ; with some of the muscles which move the 
body; with the alimentary canal and its secretions , 
which convert food into nutriment; with the organs 
of circulation — the heart, the blood-vessels, the 
lymphatics—distributing nutriment all over the 
body ; and with several organs serving to withdraw 
waste material from the body, such as the skin and 
the lungs. We must now gain an insight into a 
powerful organ, called the nervous system. It is 
distinct from all other systems in the body. The 
following are its general functions: — 

(1) It connects the different portions and organs 
of the body into an organic unit, or whole. Thus 
a violent shock to the nervous system, such as 
great anger or fear, may cause increased action 
of the heart, an accelerated pulse, and immediate 
loss of consciousness. Here, then, the nervous sys¬ 
tem acts upon the blood-vessels; these act upon the 
muscles, and this combined action causes not only 

(253) 


254 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

single portions of the body to succumb, but the 
entire body as a unit. 

(2) It animates, or governs, all movements of the 
muscles, whether these be voluntary or not. Thus, 
when a person endeavors to resist a yawn, to re¬ 
press laughter or tears, a distinct exertion of 
muscles is requisite for his effort. This is volun¬ 
tary motion prompted by an act of his will; 
whereas, the churning motion of the stomach is 
an example of an involuntary movement governed 
by the proper nerves. 

(3) It regulates the temperature, nutrition, and 
secretion of the body. Thus, sudden fear often 
produces a chilling effect in lowering the tempera¬ 
ture of the skin; weakness of the nervous system 
nearly always impairs the digestive process ; intense 
anguish frequently causes increased perspiration. 

(4) It controls the processes of nutrition. This 
may be proved by the fact that the injury of a 
nerve leading to a tissue is frequently followed by 
the waste or destruction of the tissue. 

(5) It receives impressions, which are communi¬ 
cated by its terminal branches. Lateral pressure 
against the eye-ball causes a luminous impression 
or image; this is owing to the pressure exerted 
upon the delicate terminal branches of the optic 


nerve. 


THE NERVOUS SYSTEM. 


255 



(6) It conveys impressions to different portions 
of the body. In leaping, if a person alights upon 
the heel he will feel the shocking pains in the 
back part of the head; the impression made at 
the foot is, by 
the nerves, con¬ 
veyed to the 
head. 

(7) It can gen¬ 
erate influences 
which no other 
organ or system 
can produce, 
such as sight, 
smell, taste, etc., 
etc. By virtue 
of this function, 
it puts the body 
in direct commu¬ 
nication with the 
outer worId. 

This is evident, 
for a living be¬ 


ing without the 

O 


FIG. 50. 

BRAIN AND SPINAL CORD. 

A side view of the brain and upper part 
of the spinal cord in place — the parts 
which cover the cerebro-spinal centers 
being removed. CG , the convoluted sur¬ 
face of the right cerebral hemisphere; 
Cb., the cerebellum; M. Ob., the medulla 
oblongata; B., the bodies of the cervical 
vertebrse; Sp., their spines; iV., the spinal 
cord with the spinal nerves. 


senses of sight, 
smell, taste, 
hearing, touch, and sensibility, if existing at all, 





25 () ANATOMY, PHYSIOLOGY, AND HYGIENE. 

would be utterly unconscious of the world around 
him.* 

In Structure, the nervous system, although a 
continuous substance, is conveniently subdivided 
into two systems: (1) the cerebrospinal system, 
and (2) the sympathetic system . The former 
comprises the cerebrospinal axis — that is, the 
brain and the spinal cord—together with the 
cerebral and spinal nerves which emanate from this 
axis. The sympathetic system contains the chain of 
sympathetic ganglia and the nerves which they give 
off. 

The intimate structure of this system differs from 
any tissue which we have before examined. It is 
composed of a soft, pulpy substance, which early in 
life is almost fluid, but which gradually hardens with 
the growth of the body. When examined under the 
microscope, it is found to be composed of two distinct 
elements: (1) the white substance, composing the 
larger proportion of the nervous organs of the body, 
which is formed of delicate cylindrical filaments, 


* The organs of circulation, respiration, and digestion of which 
we have already spoken are called the vegetative functions, because 
they belong also to the vegetable kingdom. The nervous system 
with its organs of sense constitute what are known as the animal 
functions , because they are found only in the animal kingdom. 



THE NEltVOUS SYSTEM. 


257 


about e-oVo an i n °h diameter, termed the nerve 
fibres; and (2) the gray substance, composed of 



FIG. 51. 

A VERTICAL SECTION OF THE CEREBRUM, CEREBELLUM AND 
MEDULLA OBLONGATA. 

Showing the relation of the cranial nerves at their origin. 1. 
The cerebrum. 2. The cerebellum with its arbor vitse represented. 
3. The medulla oblongata. 4. The spinal cord. 5. The corpus 
callosum. 6. The first pair of nerves. 7. The second pair. 8. 
The eye. 9. The third pair of nerves. 10. The fourth pair. 11. 
The fifth pair. 12. The sixth pair. 13. The seventh pair. 14. 
The eighth pair. 15. The ninth pair. 16. The tenth pair. 17. 
The eleventh pair. 18. The twelfth pair. 20. Spinal nerves. 21. 
The tentorium. 


grayish-red, or ashen-colored cells, of various sizes, 
generally possessing one or more off-shoots, which 

are continuous with the nerve-fibres just mentioned. 

17 




258 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

The gray, cellular substance constitutes the larger 
portion of the brain and is very liberal, amounting 



UPPER SURFACE OF THE CEREBRUM. 

A, Longitudinal Fissure. 

B, The Hemispheres. 

to one-fifth of all that the entire body possesses. The 
brain of man is heavier than that of any other animal, 
except the elephant and whale.* 


* Cuvier’s brain weighed 64J ounces; Webster’s, 53£ ounces; 
James Fisk’s, 58 ounces; Ruloff’s, 59 ounces; an idiot’s, 19 
ounces.— Flint. 




TIIE NERVOUS SYSTEM. 


259 


2. THE CEREBRO-SPINAL SYSTEM. 

The Brain, (Fig. 50) the seat of the mind, is 
a very soft substance, forming in man the en¬ 
larged upper terminus of the spinal cord. It is 
encased in the cavity of the cranium, which it 
fills, and from which it is difficult to be extracted 



Two Nerve Cells and Nerve Fibres from the Brain. 
Magnified 400 times. 


entire. The brain substance of man generally varies 
in weight from 40 to 60 ounces, and it is universally 
admitted that, as a rule, the quantity of brain sub¬ 
stance corresponds to the intellectual powers of the 
individual, although it is believed that the quality of 
this substance also plays an important part. The 















260 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


brain is surrounded by three membranes. The ex¬ 
ternal membrane (Dura Mater ) is thick and firm; 
the middle ( Arachnoid ) is thin, and looks somewhat 
like a spider’s web, as the name means; the inner 
(Pia Mater) consists of a network of blood-vessels. 

These membranes 
are prolonged so 
as to form a 
sheath to the 
spinal cord. The 
brain consists of 
cells and fibres 
(Fig. 53), which 
are rendered visi¬ 
ble only by a good 
microscope. The 
brain is divided 
into the large 
brain or cerebrum , 
the small brain or 
cerebellu m —a bo u t 
one-eighth as 
large as the for¬ 
mer— and the enlarged spinal cord, or medulla 
oblongata. (Fig. 51.) 

The Cerebrum in man and apes entirely cov- 



FIG. 54. 

LOWER SURFACE OF THE BRAIN. 

The numbers refer to the pairs of nerves. 






THE NERVOUS SYSTEM. 


ers the cerebellum. It entirely tills 
the front and upper part of the 
skull and is about seven-eighths 
of the entire weight of the brain. 
The cerebrum and cerebellum consist 
each of two hemispheres (Figs. 52 and 
54), one on the right, the other on 
the left side. The surface of the 
cerebrum is gray in color, consisting 
chiefly of nerve-cells, arranged so as 
to form a layer of gray matter one- 
fifth of an inch in thickness, and is 
abundantly supplied with blood-ves¬ 
sels. The interior of the brain, how¬ 
ever, is composed almost wholly of 
white substance, or nerve-fibres. It is 
covered with a great many foldings 
and windings, or convolutions, irregu¬ 
lar in form and direction (Fig. 51 ) ; 
these are separated from each other 
by deep furrows. Into these furrows 
the gray matter of the surface is 
extended, and, in this manner, its 
quantity is vastly increased. The 
extent of the entire surface of the 
brain, with the convolutions unfolded, 
is computed to be equal to four 
square feet; and yet it is easily 
inclosed within the narrow limits of 


261 



FIG. 55. 

The SDinal Cord, front 
view, with the projecting 
nerves cut off. 













262 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the skull. The gray matter is the true source of 
nervous power. 

The Cerebellum, the “little brain,” is 
placed beneath the posterior part of the cere¬ 
brum, and, like the latter, is divided into hemis¬ 
pheres. Like it, also, the surface of the 
cerebellum is composed of gray matter, and its 
interior is chiefly white matter. It has, however, no 
convolutions, but is subdivided by many parallel 
ridges, which, sending down gray matter deeply into 
the white, central portion, give the latter a somewhat 
branched appearance. This peculiar appearance has 
been called the arbor vitce , or the “tree of life,” 
from the fact that when a section of the organ is 
made it bears some resemblance to the trunk and 
branches of a tree (Fig. 51). In size, this cerebellum, 
or “little brain,” is less than one-eighth of the 
cerebrum. This part of the brain seems to control 
the voluntary muscles, particularly those of locomo¬ 
tion. Yet its exact functions are not positively 
known. 

The Medulla Oblongata (Fig. 51) preserves the 
connection between the spinal cord and the brain. 
Its columns are continuous with those of the cord, 
but contain a larger quantity of gray substance. 


THE NERVOUS SYSTEM. 


263 


Motory impressions are carried through its anterior, 
and sensitive impression its posterior columns. No 
other part of the body is so immediately important to 
the maintenance of life as the Medulla Oblongata. 

The Spinal Cord (Fig. 55) is the downward con¬ 
tinuation of the medulla oblongata. It is a soft 
substance contained in a bony cavity, formed by the 
vertebral column or back-bone. It is unlike the 
brain, in that the white matter is on the outside and 
the gray within (Fig. 56). It extends nearly to the 
sacrum ; it is furrowed like the brain into two lateral 
symmetric parts. Between these two parts — that is, 
in the center of the cord and through its entire 
length — runs a fine canal, which originates in a 
point betweeen the cerebellum and the medulla 
oblongata. 


The Cerebro-spinal Nerves originate in both the 
brain and the spinal cord, whence they ramify and 
spread all over the body (Fig. 51). They have the 
form of fibres and cells. A nervous fibre is often 
made up of minute tubes; each tube contains a 
peculiar transparent, semi-solid substance which con¬ 
tains a thick fluid. The nervous fibres terminate in 
the organs to which they lead, and there form ter¬ 
minal branches. The nervous tubes vary in size from 


264 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


ono-thouaandth of an inch to much smaller sizes; in 
the spinal cord they are much smaller; in the brain 
they are smallest. 

The Cranial Nerves are arranged in twelve pairs 
ori£rinatin<r in the base of the brain and the medulla 

n n 

oblongata (Fig. 51). 

(1) The Olfactory extend to the walls of the 
nostrils, and are nerves of smell. 

(2) The Optic , is the nerve of sight in the eye¬ 
ball. 

(3) , (4), (ft), The Motores Oculi (movers of the 
eyes) used for motion of the eye. 

(5) The Trifacial , the nerve of three branches, 
supplies the face, mouth, and tongue ; first branch to 
the upper part of the face; second to the upper jaw 
and teeth; third to lower jaw and mouth forming 
nerve of taste. Because of derangement of these 
branches we have toothache and neuralgia. 

(7) The facial , for expression of the face. 

(8) The Auditory goes to the ear and gives the 
sense of hearing. 

(9) The Glos-so-pha-ryri-ye-al to the pharynx. 

(10) The Pneumeocjastric to the lungs, heart, 
stomach, and liver. 


THE NERVOUS SYSTEM. 


265 


(11) The Accessory to the larynx. 

(12) The Hypoglossal to the tongue, giving it 
motion. 

The Spinal Nerves, thirty-one pairs in number, 
spring from each side of the cord by two roots, an 
anterior and a posterior root, which have the same 



FIG. 5(>. 

SECTION OF SPINAL CORD, WITH ROOTS OF SPINAL NERVES. 

FRONT VIEW. 


functions as the columns bearing similar names 
(Fig. 56). The posterior root is distinguished by 
possessing a ganglion of gray matter, and by 
a somewhat larger size. The successive points of 
departure, or the off-shooting of these nerves, occur 
at short and nearly regular intervals along the course 
of the spinal cord. Soon after leaving these points, 
the anterior and posterior roots unite to form the 
trunk of a nerve, which is distributed, by means of 


266 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


branches, to the various organs of that part of the 
body which this nerve is designed to serve. The 
spinal nerves supply chiefly the muscles of the trunk 
and limbs and the external surface of the body. 

The tissue composing the nerves is entirely of the 
white variety, or, in other words, the nerve-fibres ; 
the same as we have observed forming a part of the 
brain. But the nerves, instead of being soft and 
pulpy, as in the case of the brain, are dense in struc¬ 
ture, being hardened and strengthened by means of 
a fibrous tissue which surrounds each of these deli¬ 
cate fibres, and binds them together in glistening, 
silvery bundles. Delicate and minutely fine as are 
these nerve-fibres, it is probable that each of them 
pursues ail unbroken, isolated course, from its origin, 
in the brain or elsewhere, to that particular point 
which it is intended to serve. 


3. THE SYMPATHETIC SYSTEM. 

This System, like the cercbro-spinal, consists of 
cells and fibres. It is situated in front and at the 
sides of the spinal column; its ganglia, which are 
made up for the most part of small collections of 
gray nerve-cells and are the nerve-centers of this 
system, are connected with one another and with the 
spinal nerves by nerve-cords. The nerves given off 


THE NERVOUS SYSTEM. 


267 


from these ganglia chiefly follow the course of the 
blood-vessels, and are copiously distributed over the 
heart and about the stomach. 



Branches also ascend 
the muscles of the 
sense. 

In this manner 


FIG. 57. 

TIIR SYMPATHETIC GANGLIONS AND 
TIIKIR CONNECTION WITH OTHER 
NERVES. 

A, A, A t The -semilunar gang¬ 
lion and solar plexus. D, D, D , 
The thoracic (chesU ganglions. 
Ey Ey The external and internal 
branches of the thoracic ganglions. 
Gy 77, The right and left coronary 
(heart) plexus. 7, N, Q f The 
inferior, middle and superior cerv¬ 
ical (neck) ganglions. 1, The 
renal plexus of nerves. 2, The 
lumbar (loin) ganglions. 3, Their 
internal branches. 4, Their exter¬ 
nal branches. 5, The aortic plexus 
of nerves. 

into the head, and supply 


eye and ear, and other organs of 
the various regions of the body 




268 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

are associated with each other by a nervous appara¬ 
tus, which is only indirectly connected with the brain 
and spinal cord, and thus it is arranged that the 
most widely separated organs of the body are 
brought into close and active sympathy with each 
other, so that “ if one member suffers, all the other 
members suffer with it.” From this fact, the name 
sympathetic system , or the great sympathetic nerve , 
has been given to the complicated apparatus we have 
briefly described. Blushing and pallor are caused by 
mental emotions, as modesty and fear, which produce 
opposite conditions of the capillaries of the face by 
means of these sympathetic nerves. 

The following from a very interesting writer will 
be appreciated here :— 

“ Buried in the hidden recesses of the body, be¬ 
tween the spinal column and the great organs of 
uutrition, there is a double row of small knots of 
nervous substance, bound together by a series of 
nerves running from one to another, in succession, 
from the neck to the base of the column. The 
whole appears like a long, fine cord, with knots 
at various distances — a collection of little brains, 
if I may use a rather crude expression. It is, as 
the Swiss would say, the 4 great council ’ of this 
federative republic, which counterpoises that cere¬ 
bral royalty within us. It has been well named the 


THE NERVOUS SYSTEM. 


269 


great sympathetic nerve, and this it is which makes 
the laws by which our interior life is governed. 
The nutritive apparatus of a country, its commerce, 
its industry, the incessant labor of its citizens, by 
which the public wealth is built up — and also, let 
us add, the throbs of the national heart — all this 
the sympathetic system full plainly shows us should 
be left to itself. It would be a fine affair if the 
brain had to watch over the service of the stomach 
or if, at its convenience, it regulated the movements 
of the master who disposes of its life. Besides, 
what would become of the poor body, if the least 
drowsiness attacked the universal center? Happy 
is it for us — and let us not be slow to own it — 
that nature has armed herself against these encroach¬ 
ments of power .”—Maces The Little Kingdom . 

4. THE FUNCTIONS OF THE NERVOUS 
SYSTEM. 

The Functions of the Brain. — The thin layer of 
gray matter upon the hemispheres of the larger and 
smaller brain is intimately associated with mental 
operations. The reason for the convolutions and 
fissures on the surface of the brain is evident: they 
cause the layer of gray matter to be more extensive, 
and, consequently, other things being equal, to in- 


270 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


crease in quantity with the increase of convolutions 
and fissures. There are strong reasons why the 
main function of the cerebral hemispheres, and 
more especially that of the gray matter, seems to 
be the manifestation of intellectual powers and of 
powers of the will, viz.: — 

(1) In the animal kingdom, there is generally a 
correspondence between the quantity of gray matter, 
depth of convolutions, and the sagacity of the animal. 

(2) The gray matter of the brain is much more 
smooth during the first period of the infant’s life, 
and its increase corresponds with the development 
of intelligence. 

(3) In diseases which have been known to com¬ 
mence at the circumference of the brain, and to 
pass toward the center, medical observations have 
found that the faculties of the mind are affected first; 
while in those diseases which commence in the ceutral 
parts of the brain, and thence pass towards the 
circumference, they are affected last. 

(4) Experiments upon animals show that when the 
brain is gradually sliced away, the animal grows more 
dull and stupid as the quantity of brain cut away 
increases. 

Mental Derangement may be caused by (1) 
imperfect nutrition of the brain; (2) insufficient or 


THE NERVOUS SYSTEM. 


271 


excessive flow of blood toward the brain ; (3) a per¬ 
verse condition of the blood; (4) prolonged sleep¬ 
lessness; (5) deep affliction or despondency. The 
usual symptoms of progressing derangement are 
weakened attention and loss of memory, which should 
be promptly met by avoidance of physical or nervous 
excitement, and by proper attention to the body. 
Insanity , a more continuous state of mental derange¬ 
ment, often springs from like sources, but sometimes 
from hereditary predisposition. Insanity is charac¬ 
terized by lack of appreciation of the proper relations 
between the self and the external world. 

As persons can live though one of their lungs 
may be seriously injured, so life is not necessarily cut 
off in case one of the cerebral hemispheres has been 
damaged.* 

The Functions of the Cerebellum, although not 


* A pointed iron bar three and a half feet long and one inch 
and a quarter in diameter, was driven by the premature blasting 
of a rock, completely through the side of the head of a man who 
was present. It entered below the temple, and made its exit at 
the top of the forehead, just about the middle line. The man was 
at first stunned, and lay in a delirious, semi-stupefied state for 
about three weeks. At the end of sixteen months, however, he 
was in perfect health, with wounds healed and mental and bodily 
functions unimpaired, except that the sight of the eye of the 
injured side was lost.— Dalton. 



272 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


distinctly known us yet, seem to be the regulation of 
muscular movement. 


The Function of the Medulla Oblongata consists 
in generating and controlling the motions of res¬ 
piration and deglutition. It likewise gives rise to 
certain nerves, which are here called cranial nerves 
(from cranium , the skull). All except two of these 
important nerves spring from the medulla, or the 
parts immediately adjoining it; the exceptions are 
the two nerves taking part in the special senses of 
sight and smell, which nerves have their origin at 
the base of the cerebrum. 



The decussation , or crossing of nerve fibres occurs 
in this section of the brain. (Fig. 58). 

Hence the fact 
should be observed in 
this connection, 
namely, this cross 
action does not 
usually take place in 
the cranial nerves. 
Accordingly, when apoplexy, or the rupture of a 
blood-vessel, occurs in the right hemisphere of the 
cerebrum, the left side of the body is paralyzed, but 
the right side of the face is affected; this is because 
that part of the body is supplied by the cranial nerves 


FIG. 58. 

NERVE- FILAMENTS. 

Decussion with their Sheath. 



THE NERVOUS SYSTEM. 


273 


which cross over to the other side in passing down 
through the medulla. 

The brain, cerebellum and the spinal cord can be 
sliced away one after the other without immediately 
destroying life; whereas, an interference with the 
medulla oblongata is followed by instantaneous 
death. 

Functions of the Spinal Cord. — 1. To transmit 
sensitive impressions from its outer nerves to the 
brain. 2. To transmit the manifestations of the will 
from the brain to the spinal-motor nerves, which 
result in muscular activity. 3 To originate nerve- 
force independently of the brain whenever a stimu¬ 
lus is applied. Thus, when a stimulus, such as a 
drop of acid, is applied to the upper leg of a 
decapitated frog, he brings the toes of the corre¬ 
sponding foot to the place to wipe off the acid, but 
he will not leap away. In this case an impression 
has been made upon a sensitive nerve leading to 
the spinal cord. This sensitive or sensory nerve 
conveyed the impression to the spinal cord, the 
spinal cord made response to the impression 
through a motor nerve, and this response resulted 
in the reflex action of the foot. So when, inde¬ 
pendent of any influence of the brain, a small piece 
of bread is passed into the gullet by voluntary 

18 


274 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


motion, it will be urged onward to the stomach by 
involuntary motion — that is, by the reflex action of 
the spinal cord. The bread here acts as an exciting 
stimulus upon the spinal marrow, which generates 
motor power; this motor power is “ reflected’’ back 
and produces the involuntary movements or reflex 
action of the muscles whose sensitive fibres • were 
stimulated. 

The cord by an accident may be so injured as to 
cut off all sensation and voluntary motion in the legs, 
the person apparently lifeless and powerless from the 
waist downward. By pinching the foot the leg will 
jerk and even kick with some force. The subject 
will be unconscious of the act, and unless he is look¬ 
ing at the leg will not know it. This is not due to 
the muscle itself for if the cord is diseases below 
the point of injury, this contraction will not occur. 
To produce this form of nervous action, three things 
are requisite — (1) a nerve to conduct messages from 
the surface of the body, one of that which is called 
sensory, but which is now known to be incapable of 
awakening sensation; (2) a portion of uninjured 
spinal cord, which shall reflect or convert impressions 
into impulses; and (3) a motor nerve to conduct im¬ 
pulses outward to the muscles. The power of the 
cord to enforce reflex acts resides in the gray matter, 
into which the reflex nerves enter. 


THE NERVOUS SYSTEM. 


275 


Direction of the Fibres of the Cord.— If one 
lateral half of the spinal cord be cut, or injured, a 
very singular fact is observed. All voluntary power 
over the muscles of the corresponding half of the 
body is lost, but the sensibility of that side remains 
undiminished. This result shows that the motor 
fibres of the cord pursue a direct course, while its 
sensory fibres are bent from their course. And this 
has been proved to be the fact; for immediately 
after the posterior roots — the conductors of sensory 
impressions—join the posterior columns, they enter 
the gray matter of the cord, and passing over, ascend 
to the brain on the opposite side. Accordingly, the 
sensory fibres from the right and left sides interlace 
each other in the gray matter; this arrangement has 
been termed the decussation , or crossing of these 
fibres (Fig. 58). This condition serves to explain 
how a. disease or injury of the cord may cause a 
paralysis of motion in one leg, and a loss of sensation 
in the other. 

The direction of the anterior, or motor columns of 
the cord, is downward from the brain. In the cord 
itself, the course of the motor fibres is for the most 
part a direct one ; but in the medulla oblongata, or 
upper extremity of the cord, and therefore early in 
their career, these fibres cross from side to side in a 
mass, and not separately, as in the case of the 


276 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

posterior fibres just mentioned. This arrangement is 
termed the decussation of the anterior columns of the 
medulla. 

From this double interlacing of fibres results a 
cross action between the original and terminal ex¬ 
tremity of all nerve-fibres which pass through the 
medulla — namely, those of all the spinal nerves. 
Consequently, if the right hand be hurt, the left side 
of the brain feels the pain ; and if the left foot move, 
it is the right hemisphere which dictates its move¬ 
ment. For the same reason, when a loss of sensation 
and power of motion affecting the right side of the 
body alone is observed, the physiologist understands 
that the brain has been invaded by disease upon its 
left side. This affection is termed hemiplegia , or the 
“ half-stroke/’ The full-stroke, which often follows 
the rupture of a blood-vessel in the brain, is called 
paralysis. 

Tlie Functions of tlie Sympathetic System are 
not fully known as yet. It would appear, however, 
that while it is intimately connected with the other 
divisions of the nervous system, it presides over the 
actions of the alimentary canal, the glands, the 
blood-vessels and the heart. The heart may be 
removed from the body, and yet its rhythmical 
movements will continue for a number of minutes. 


THE NERVOUS SYSTEM. 


277 


This independent motor power on the part of the 
heart can only be explained by the existence of sym¬ 
pathetic ganglia or centers linked together by 
delicate nerve filaments, constituting of themselves 
a distinct nervous system. 

An important use of the sympathetic nerve seems 
to be a communication of one part of the system 
with another, so that one organ can take cognizance 
of the condition of every other, and act accordingly. 
If, for example, disease seizes the brain, the stomach, 
by its sympathetic connection, knows it; and as 
nourishment would add to the disease, it refuses to 
receive food, and perhaps throws off what has already 
been taken. Loss of appetite in sickness is thus a 
kind provision of nature, to prevent our taking food 
when it would be injurious; and following this intima¬ 
tion, we, as a general rule, should abstain from food 
until the appetite returns. 

Functions of Nerves. — If the nerve of a tooth be 
divided, the tooth has lost its sensibility. If the 
nerves leading to the biceps be severed, this muscle 
loses its motor power; it will no longer move the 
forearm. If these nerves be exposed in their course 
and irritated, the biceps will be thrown into violent 
movements, and intense pains experienced as coming 
from the biceps. These facts show that the nerves, 


278 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

generally speaking, are endowed with motor and sen¬ 
sory properties. That is to say, the nerves enable us 
to seize ordinary sensations, and to perform acts of 
motion. 

There are nerves which are specially engaged in 
motion, and others, such as the optic nerve, which 
generate merely sensations. Either class may be in¬ 
jured without any damage to the other. Thus, a blind 
man rolling his eyes shows that, though his optic 
nerve is blighted, the motor nerves are in full action. 
So a limb may b q paralyzed — that is, deprived of all 
motion — and yet be very sensitive. If a motor nerve 
be divided, and a galvanic current applied to the por¬ 
tion of the nerve connected with the muscle, the mus¬ 
cle contracts. This shows that motor nerves act like 
telegraphic wires. 

Cases have been known where soldiers complained 
of pain in their limbs, which had long before been 
amputated. This is evidence that sensory nerves act 
like insulated wires, and, besides, that we refer pain 
and all other sensations to the parts which are sup¬ 
plied with nerves; we suppose the sensation to exist 
in the direction from which the nerves communicate 
it. 

The nerves leading from the brain to the eye, ear, 
etc., etc., are in pairs; also those originating in the 
spinal cord. The latter are distributed nearly over 


THE NERVOUS SYSTEM. 


279 


the whole body, and are endowed with both motor and 
sensory properties. 

By reference to Fig. 56, it will be observed that 
each spinal nerve has two roots, a posterior and an 
anterior . It is believed that the fibres springing from 
the posterior root are those of the nerve which convey 
sensation; and the fibres which originate in the ante¬ 
rior root convey the motory impulse. This is known 
because when the posterior root i3 cut the animal loses 
the power of feeling; and when the anterior root is 
cut, that of motion. 


280 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


REVIEW QUESTIONS. 

1. What are the vegetative functions? 

2. What are the animal functions? 

8. Name the subdivisions of the Nervous System. 

4. What is the structure of the Nervous System? 

5. Make a drawing of the brain from Fig. 51. 

6. What kind of matter predominates in the brain? 

7. What is the seat of the mind? 

8. What is the weight of the brain substance? 

9. Name the coverings of the brain. 

10. Describe the Cerebrum. 

11. What is the extent of the entire surface of the brain? 

12. What is the true source of nerve power? 

13. Describe the Cerebellum. 

14. What is the arbor vitce? 

15. What is the ratio of the Cerebellum to the Cerebrum in 
size? 

16. What is the Medulla Oblongata? 

17. Describe the Spinal Cord. 

18. Make a drawing of its cross-section, Fig. 56. 

19. Name the pairs of Cranial Nerves and tell office of each. 

20. How many pairs of Spinal Nerves are there? 

21. How do they originate? 

22. What can you say of the tissue forming the nerves? 

23. What is the Sympathetic System? 

24. Where is it? 

25. What office does it perform? 

26. To what does Mace compare it? 

27. Tell the functions of the brain. 


T1IE NERVOUS SYSTEM 


281 


28. State the causes of mental derangement. 

29. What is insanity? 

30. What are its causes? 

31. May the brain be cut away without causing death? 

32. Describe a remarkable incident. 

33. What seems to be the functions of the Cerebellum? 

34. Tell the functions of the Medulla Oblongata. 

35. Wliat is decussation? 

36. Discuss the subject of apoplexy. 

37. Where is the seat of life? 

38. State the three functions of the Spinal Cord. 

39. What is reflex action? 

40. What things are requisite to produce this action? 

41. State some uses of reflex action? 

42. What can you say as to direction of the fibres of the 
cord? 

43. What are the functions of the Sympathetic System? 

44. What are the functions of Nerves? 

45. What are sensor nerves? motor nerves? 

46. Give a quotation from Dr. Holmes about the Nervous 
System. 


282 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


5. THE ORGANS OF SENSE. 

Introduction.— The ideas, words and actions of a 
human being are largely dependent upon the sound¬ 
ness and the training of his sensory organs. 

Sensory organs are tools, or instruments, capable 
(1) of receiving impressions from the outer world, 
and (2) of making us conscious of those impressions. 
The means by which consciousness of impressions 
arises is sensation. Thus, the eye with its proper 
nerves is a sensory organ; it is capable of receiving 
the impression that a certain ribbon is blue; there 
is no other organ which can obtain such an impres¬ 
sion. The eye, besides being capable of receiving 
that impression, is also capable of making us 
conscious of it, viz., the blue color. A man, after 
his eyes were removed, would be utterly incapable 
of recognizing the blue tint, although his mind were 
never so clear. 

Sensation, in the present example, is excited by 
the action of the blue rays upon the retina; so we 
speak of the sensation of cold, meaning by it the 
peculiar effect which cold has upon the nerves. 

Nearly all sensations come from without the 
body — that is, from the outer world; they may be 
called objective sensations. The yellow color of a 


THE NERVOUS SYSTEM. 


283 


lemon, the blue color of a ribbon, are objective sen¬ 
sations. It sometimes happens that the nerves of a 
sensory organ are affected when there is no object¬ 
ive or outside cause whatever. In this case they 
make us believe things that have actually no exist¬ 
ence. The eye, for example, if closed and pressed 
upon with a finger, develops a luminous image; this 
sensation is drawn not from the exterior world, but 
solely from within the body, hence, is not objective, 
but subjective . The peculiar noise known as the 
“ humming of the ear ” is also a subjective sen¬ 
sation. 

The sensory organs are five in number, viz., that 
of sight , hearing , touch , taste and smell . They are 
merely the peculiarly shaped termination of a par¬ 
ticular nerve. Impressions acting upon this termi¬ 
nation, or anywhere upon the nerve, whether coming 
from within the body or from without, affect it in a 
way that is peculiar to it, and concerning which 
nothing positive is known. Thus the eye-ball is so 
constructed as to collect a great number of rays of 
light which affect the optic nerve, and thereby pro¬ 
duce the sensation of sight. What becomes of this 
sensation — that is, in what manner it produces the 
consciousness of sight, and in what manner it ulti¬ 
mately serves intellectual functions, we do not 
know, and probably never shall. The ear is utterly 


284 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


blind to the minute waves of light but very sensi¬ 
tive to the aerial waves of sound. So each organ 
has a distinct structure, in virtue of which it has its 
particular manifestations; and the different senses 
may be compared to the various departments of 
government in a country, all of which together 
make up the government itself. 


TOUCH. 

The Sense of Touch is possessed by nearly all por¬ 
tions of the general surface of the body, but it finds 
its highest development in the hands. The human 
hand is properly regarded as the model organ of 
touch. The minute structure of the skin fits it 
admirably for this form of sensation; the epidermis, 
or scarf-skin, is fine and flexible, while the dermis, 
or true-skin, contains multitudes of nerve-filaments, 
arranged in rows of papillce or cone-like projections, 
about one one-hundredth of an inch in length. It is 
estimated that there are 20,000 of these papillse in a 
square-inch of the palmar surface of the land. Now, 
although the nerves of the dermis are the instruments 
by which impressions are received and transmitted to 
the brain, yet the epidermis is essential to the sensation 
of touch. This is shown by the fact that whenever 
the true-skin is laid bare, as by a burn or blister, the 


THE NERVOUS SYSTEM. 


285 


only feeling that it experiences from contact is one of 
pain, not that of touch. 



FIG. 59. 


The office of the epidermis is thus made evident; 
it is to shield the nerve-filaments from direct contact 
with external objects. At the tips of the fingers, 
where touch is most delicate, the skin rests upon a 
cushion of elastic material, and receives firmness and 
permanence of shape by means of the nail placed 
upon the less sensitive side. Besides these favorable 
conditions, the form of the arm is such, and its 
motions are so easy and varied, that we are able to 
apply the test of touch in a great number of direc¬ 
tions. The slender, tapering fingers, with their 
pliant joints, together with the strong opposing 
thumb, enable the hand to grasp a great variety of 
objects; so that, great as are the delicacy and grace of 
the hand, it is not wanting in the elements of power.* 

* The sense of touch cannot always be relied upon. This may 
be shown by the experiment of Fig. 59, 




286 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Pressure , resistance , smoothness , roughness , hard¬ 
ness , softness , also cofoZ, and are the most com¬ 

mon sensations excited by the sense of touch. 

Different portions of the body possess different 
degrees of sensibility; compare the acuteness of the 
finger tips with the dullness of the neck. The 
amount of sensibility is greatly lessened when the 
skin is stretched. 

A person who takes hold of an exceedingly cold 
iron bar experiences a sensation nearly like that 
obtained by touching one overheated. The tooth¬ 
ache caused by the contact of a tooth with ice cream 
is the same as that resulting from severe heat applied 
to the tooth. These well-known facts show that an 
excess of cold or heat causes pain instead of impres¬ 
sion of temperature; the pain is the same, by which¬ 
ever it may be caused. 

Beyond the dermis the nerves are insensible to 
heat and cold; so the optic nerve, beyond its ex¬ 
pansion— the retina — is no longer sensitive to light. 

The sense of touch is capable of great develop¬ 
ment. “Professor Saunders, of Cambridge, who 
lost his sight when two years old, could distin¬ 
guish by this sense genuine medals from imitation 
ones. Other blind men have, by their exquisite 
touch, been enabled to become sculptors, concholo- 
gists, botanists,” etc., etc. 


THE NERVOUS SYSTEM. 


287 


THE TASTE. 

The Chief Organ of Taste is the upper surface 
of the tongue; though the lips, the palate, the 
internal surface of the cheeks, and the upper part 
of the oesophagus, participate in this function. 

The Tongue is a double organ, composed chiefly 
of muscular fibres, 
which run in almost 
every direction. The 
two sides are so 
perfectly distinct, 
that sometimes, in 
paralysis, one side is 
affected, while the 
function of the other 
remains perfect. It 
possesses great ver¬ 
satility of motion, 
and can be moulded 
into a great variety 
of shapes. In artic¬ 
ulation, mastication, 
and deglutition, the 
tongue is an auxiliary late or entrenched ( H , LV, E } F, G, 
to other organs. nerves; C , glottis — Lankester. 



fig. 60 . 


The Tongue, showing the three 
kinds of Papillse— the conical ( D ), 
the whip-like (if, /,) the circumval- 


288 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

This organ is abundantly supplied with blood¬ 
vessels, having a large artery sent to each side of 
it. It is also very largely furnished with nerves; 
it receives nervous filaments from the fifth, ninth, 
and twelfth pairs of nerves. The branch of the 
fifth, called the gustatory, is the nerve of taste and 
sensibility; the twelfth, called the hypo-glossal, of 
voluntary motion. By means of the ninth, called 
the glosso-pharyngeal the tongue is brought into 
association with the fauces, oesophagus, and larynx. 

The surface of the tongue is thickly studded with 
fine papillae * which gives the organ a velvety 
appearance. (Fig. 60). Into these the nerve fila¬ 
ment enter and terminate. 

Sweetness , acidity and pungency are sensations 
most frequently excited by this sense. 

Mere contact with the surface of the tongue, 
however, is not sufficient, but contact with the ex¬ 
tremities of the nerves of taste within the papillae is 
required. In order that the substance to be tasted 
may penetrate the cells covering the nerves, it must 
either be liquid in form, or readily soluble in the 
watery secretion of the mouth —the saliva. The 
tongue must be moist also. If the substance be in- 


* By applying strong acids, as vinegar, to the tongue, with 
a hair pencil, these points will become curiously lengthened. 



THE NERVOUS SYSTEM. 


289 


soluble — as glass or sand — or the tongue dry, the 
sense of taste is not awakened. In sickness, 
when the tongue is heavily coated, the taste is very 
defective, or, as is frequently expressed, “ nothing 
tastes aright.” 

All portions of the tongue are not alike endowed 
with the sense of taste, that function being limited to 
the posterior third, and to the margin and tip of this 
organ. The soft palate, also, possesses the sense of 
taste; hence, an article that has an agreeable flavor 
may very properly be spoken of as palatable, as is 
often done. All parts of the tongue do not perceive 
equally well the same flavors. Thus, the front 
extremity and- .margin, which is the portion supplied 
by the “fifth pair” of nerves, perceives more 
acutely sweet and sour tastes; but the base of the 
tongue, supplied by the glossopharyngeal nerve, is 
especially sensitive to salt and bitter substances. 
The nerve of the front part of the tongue, as before 
stated, is in active sympathy with those of the face, 
while the relations of the other nerve are chiefly with 
the throat and stomach ; so that when an intensely 
sour taste is perceived, the countenance is involun¬ 
tarily distorted, and is said to wear an acid expres¬ 
sion. On the other hand, a very bitter taste affects 
certain internal organs, and occasions a sensation of 
nausea, or sickness of the stomach. 


10 


290 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

The sense of taste varies greatly in different per¬ 
sons; it depends upon education, habits, and often 
upon imagination. 

The sensations of taste are largely connected with 
those of other senses, such as smell, touch, and even 
sight. Thus, when the nose is held tightly closed so 
as to obtain no smell, the taste of many a substance 
is rendered difficult to distinguish; and it is very 
nearly the same if the sense of sight is interfered 
with. 


SMELL. 

% 

The Sense of Smell is located in the nasal cavi¬ 
ties, or air passages, of the nosev This organ is 
composed of cartilage, mucous membrane, and mus¬ 
cles covered with an integument. It is joined to 
the skull by small bones. The nasal cavities open 
behind into the pharynx. The mucous membrane, 
which lines the interior of the nose, is continuous 
with the skin externally, and with the lining mem¬ 
brane of the parts of the throat. The entrance of 
the nostrils is provided with numerous hairs, which 
serve as guardians to the delicate membrane of the 
nose. 

The nasal cavities (nasal fossae) are. irregular in 
shape, bounded above by the sphenoid and ethmoid 
bones of the skull; below by the hard palate. They 


THE NERVOUS SYSTEM. 


291 


are separated from each other by the septum , a thin 
bony tissue, while upon the outer wall of each 
nostril, in the dried skull, are three projecting pro¬ 
cesses, termed spongy bones. In life these are 
covered by a mucous membrane. These turbinated 
bones give more surface for the distribution of the 
fibres of the olfactory nerve. This nerve ramifies 
the upper part of the nostrils while in the lower 
and front part, for 
the sensibility of 



touch and pain, 
are branches of 


the “fifth pair” 
of nerves. An 
irritation applied 
to the parts where 
this nerve is dis¬ 
tributed occasions 


FIG. 61 . 


sneezing — that is, section of the right nasal cavity. 
a spasmodic con¬ 
traction of the diaphragm, the object of which is 
the expulsion of the irritating cause. The man¬ 
ner in which the olfactory nerve-fibres terminate is 
peculiar. Unlike the extremities of other nerves, 
which are inclosed by a greater or less thickness of 
tissue, these come directly to the surface of the 
mucous membrane, and thus are in very close con- 



292 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

tact with the odorous particles that are carried along 
by the respired air. The surface is at all times 
kept in a moist condition by an abundant flow of 
nasal mucus ; otherwise it would become dry, hard, 
and insensitive from the continual passage of air to 
and fro in breathing. 


The Use of the Sense of Smell is to discern the 
odor or scent of any thing. When substances are 
presented to the nose, the air that is passing through 
the nostrils brings the odoriferous particles of matter 
in contact with the filaments of the olfactory nerves, 
that are spread upon the membrane that lines the 
air-passages, and the impression is then trans¬ 
mitted to the brain. 

This sense, with that of taste, aids man, as well as 
the inferior animals, in selecting proper food, and it 
also gives us pleasure by the inhalation of agreeable 
odors. The sense of smell, like that of taste and 
touch, may be improved by cultivation. It likewise 
varies in different persons. 

Sometimes this sense seems to possess a morbid 
degree of acuteness in respect to odors, which is 
highly inconvenient and even dangerous. With some 
individuals, the smell of certain fruits, flowers, 
cheese, etc., produces nausea and even convulsions. 

As a rule, wo judge localities with strong odors to 


THE NERVOUS SYSTEM. 


293 


be unhealthy. The escape of illuminating gas is 
easily detected by its odor, and may be fatal to the 
inmates of a room. Many strong odors, however, 
are harmless, while on the other hand, quite inodor¬ 
ous atmospheric air may contain the germs of the 
most dangerous epidemics. Such is the case with the 
air of low grounds, marshes and swamps. The con¬ 
nection between bad odors and pernicious effects is 
not yet cleared up; the production of odor i3 closely 
connected with that of chemical action.* 


* “ I have not seen it anywhere laid down as a general rule, 
but I believe it might be affirmed, that we are intended to be 
impressed only sparingly and transiently by ordor. There is a 
provision for this in the fact that all odors are vapors or gases, 
or otherwise volatile substances; so that they touch but the 
inside of the nostril, and then pass away. 

“ In conformity with this fleeting character of odorous bodies, 
it is a law in reference to ourselves, to which, as far as I know, 
there is no exception, that there is not any substance having a pow¬ 
erful smell of which it is safe to take much internally. The most 
familiar poisonous vegetables, such as the poppy, hemlock, hen¬ 
bane, monk’s-hood, and the plants containing prussic acid, have 
all a strong and peculiar smell. Nitric, muriatic, acetic, and 
other corrosive acids, have characteristic potent odors, and all are 
poisons. Even bodies with agreeable odors, like oil of roses, or 
cinnamon, or lavender, are wholesome only in very small quan¬ 
tities, and, when the odor is repulsive, only in the smallest quanti¬ 
ties. So far as health is concerned, the nostril should be but 
sparingly gratified with pleasing odors or distressed by ungrateful 



294 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


SIGHT. 

The Eye, the apparatus concerned in the sense of 
sight, consists of the eyeball , optic nerve , muscles of 
motion , and protecting organs. The eyeball is con¬ 
tained within a bony cavity, called the orbit of the 
eye. In this situation it is not only protected from 
injury, but is insured the most excellent range of 
vision. It is acted upon by six muscles, by which 
the pupil can be directed to almost any point. They 
are attached, at one extremity, to the bones of the 
orbit behind the eye and at the other to the eyeball 
just behind the cornea. It is by the permanent 
shortening of some of these muscles that we have the 
condition called strabismus or cross-eye. 

The Eyeball, or globe of the eye, is spherical in 
shape, and has three sets of coats or tunics: 1st. The 
sclerotic and cornea. 2d. The choroid , iris , and 
ciliary processes. 3d. The retina. The humors , or 
contents of the eyeball, are also three in number: 
1st. The aqueous , or watery. 2d. The crystalline 
(lens). 3d. The vitreous , or glassy. The sclerotic 
coat is a white fibrous membrane, and covers aboutT 


ones. No greater mistake can be made in the sick-room than 
dealing largely in perfumes.” — Wilson. 



THE NERVOUS SYSTEM, 


295 


four-fifths of tlio external surface of the eyeball. It 
is known as “the white of the eye,’’ and anteriorly 



THE EYEBALL IN ITS SOCKET, WITH TIIE MUSCLES THAT MOVE IT. 

At the right is seen the projecting nasal bone, with part of the 
cheek-bone; the eye rests on the latter. Through the transparent 
cornea, the pupil fs faintly seen. 2, external rectus muscle, cut 
and turned down to expose the back of the eye; 3, internal rectus; 
4, inferior rectus; 5, superior rectus; 6, superior oblique, running 
through the pulley; 7, 8, inferior oblique; 9, elevator of the 
upper lid. The optic nerve projects from the back of the eye as a 
cord of considerable size; a portion has been cut away. 

it presents a beveled edge, which receives the circu¬ 
lar projecting portion of the eye (cornea) in the 
same manner that a watch crystal is received by the 


UV 


296 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

groove in its case. The cornea is the transparent 
projecting layer, which forms the anterior one-fifth 
of the ball of the eye. It is concavo-convex, and 



FIG. 63. 


VERTICAL SECTION THROUGH THE EYE ON THE MIDDLE LINE. 

A, Cornea. B, Anterior Chamber. C , Pupil. D t Iris. E, 
Crystalline. F , Zone of Zinn, forming the anterior wall of Canal 
of Petit. G } Ciliary Process and Circle. U, Sclerotic. I, Choroid. 
K t Retina. L , Vitreous Body. M, Optic Nerve. N, Right 
Inferior Muscle. 0, Right Superior Muscle. P, Levator Muscle 
of Eyelid. Q, Lachrymal Glands. R, Lachrymal Canal. 

entirely transparent; its blood-vessels being so small 
that they exclude the red particles of the blood, 
altogether, and admit nothing but the serum, by 



















THE NERVOUS SYSTEM. 


297 


which it is nourished. The choroid is a highly vascu¬ 
lar membrane, its external surface being a rich choco¬ 
late brown, and its internal a deep black. It invests 
the posterior five-sixths of the globe, and extends as 
far forward as the cornea. The iris is the circular 
shaped curtain 
which hangs be¬ 
hind the cornea, 
presenting in its 
center a circular 
aperture, termed 
the pupil . This 
membrane is com¬ 
posed of two lay¬ 
ers, the radiating 
fibres of the an¬ 
terior layer con¬ 
verging from cir- 

O O 



cum fere rice to Viewed from behind and showing 
center, and the Suspensory Ligament, Iris, and Pupil, 
fibres of the pos 

terior layer, being circular, surrounding the pupil. 
By the action of the radiating fibres the pupil dilates, 
and by the action of the circular fibres, it contracts. 
The ciliary processes are composed of a number of 
triangular folds, formed by the choroid coat with 
which they are continuous. The retina ,, the internal 



298 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

coat, is a delicate nervous membrane, upon the sur¬ 
face of which the images of external objects are 
impressed. Three layers enter into the structure of 
the retina; namely, the external , the middle or 
nervous , and the internal or vascular. The external 
layer is a very thin film; the middle layer is the 
expansion of the optic nerve; and the internal con¬ 
sists of the ramifications of a minute artery and its 
accompanying vein. The aqueous humor completely 
fills the anterior and posterior chambers of the eyeball. 
The anterior chamber is the space between the cornea, 
in front, and the iris, behind; while the posterior 
chamber is the very narrow space bounded by the 
iris in front, and by the crystalline lens and the 
ciliary processes, behind. The crystalline lens or 
humor , is situated immediately behind the pupil, and 
is surrounded by the ciliary processes. The lens is 
composed of a soft substance, arranged in layers, 
very much after the manner of the coats of an onion. 
It is double convex in shape and is imbedded in 
the anterior part of the vitreous humor, from which 
it is separated by a thin membrane. It is also 
invested by a thin, elastic, and transparent mem¬ 
brane, known as the capsule of the lens. By the 
action of the ciliary processes upon the lens and its 
capsule, the degree of its convexity is changed, and 
we are thus enabled to view objects at a distance, 



THE NERVOUS SYSTEM. 


299 


as well as examine those very near the eye. With¬ 
out this ability to change the degree of convexity of 
the lens, or the power of adaptation, as it is called, 
vision would be confined to objects at certain definite 
distances only. The clouding of the lens, or any 
changes in its structure that prevent the rays of light 
from passing through it to the retina, constitute the 
affection known as cataract of the eye. The vitreous 
humor fills about four-fifths of the entire eyeball. 
It is perfectly transparent, and is of the consistence 
of jelly. It differs from the other humors, in that if 
it once escapes from the globe, the sight of the 
eye is irrecoverably lost, while the aqueous humor 
is capable of being renewed. 

The Protecting Organs are the orbits , eyebroivs , 
eyelids , and the lachrymal or tear apparatus. The 
orbits are the bony sockets in which the eyeballs are 
situated. They are lined with cushions of fat, and 
pierced through the bottom by a large hole, giving 
passage to the optic nerve. The eyebrows are so 
arranged that they prevent the moisture that accum¬ 
ulates on the forhead, in free perspiration, from 
flowing into the eye, and also shade these organs 
from too bright a light. The eyelids , as every one 
knows, are two movable curtains placed in front of 
the eyes. On the outside they have a delicate skin, 


300 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

with muscular fibres beneath, and a narrow cartilage 
on their edges, serving to preserve the shape of the 
lid. The lids are lined with a delicate membrane, 
which is reflected over the front of the eye. 
This membrane is called the conjunctiva , and is 
subject to very severe forms of inflammation known 
as conjunctivitis . The natural secretion of the con¬ 
junctiva is a fluid, which serves the purpose of lubri¬ 
cating the eye, and of allowing the lids to open 
and shut without friction. The edges of the lids 
are furnished with a row of hairs, called eyelashes, 
which naturally curve upward from the upper lid, 
and downward from the lower, so that they may 
not become entangled with each other in the clos¬ 
ure of lids. Their purpose is that of protecting 
the eyeball from dust, and of spreading the lubri¬ 
cating fluid equally over the surface of the eye. 
The lachrymal apparatus which secretes the tears 
consists of the lachrymal gland with its ducts , 
lachrymal canals , and the nasal duct. The lachrymal 
gland is situated at the upper and outer angle of the 
orbit. It is flattened and oval in shape, about 
three-quarters of an inch in length, and has, passing 
from it, ten or twelve small ducts which open upon 
the upper lid, where they pour upon the conjunctiva 
the tears. This secretion is kept up continually, 
walking or sleeping, thus causing the eyes to be 


THE NERVOUS SYSTEM. 


301 


constantly moist. The lachrymal canals begin at 
minute openings upon the free borders of each 
eyelid, near the inner angle of the eye, by two 
small orifices called puncta lachrymalia (tear 
points). Each of these 
points communicates with 
the nasal duct. The nasal 
duct is a short canal, about 
three-quarters of an inch 
in length, directed down¬ 
ward and backward from 
the inner angle of the eye 
to the inferior channel of 
the nose. The tears are 
therefore secreted by the 
lachrymal glands, conveyed 
to the eye by the small 
ducts, taken up by the 
puncta lachrymalia into the 
lachrymal canals, and 
thence carried through the 
nasal ducts into the nasal passages. 



FIG. 65. 

1, The lachrymal gland. 
2, Ducts leading from the 
lachrymal gland to the 
upper eyelid. 3, 3, The 
puncta lachrymalia. 4, 
The nasal sac. 5, The ter¬ 
mination of the nasal duct. 


The Physiology of Vision.—-As regards the func¬ 
tions of the different parts of the globe of the eye, 
the sclerotic coat not only gives form to the organ, 


302 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

but, by its dense fibrous structure, gives protection 
to the interior and more delicate parts. The cho¬ 
roid coat consists chiefly of a tissue of nerves and 
small blood-vessels; the latter give nourishment to 
the eye. Another very important office of this coat 
is to absorb the rays of light immediately after they 
have passed to the retina. This is effected by the 
inner lining of its surface, which is composed of 
black pigment. Light would be too intense were it 
not for this provision, and vision confused and indis¬ 
tinct. The iris, by means of its powers of expan¬ 
sion and contraction, regulates the amount of light 
admitted through the pupil. Persons unacquainted 
with the structure of the eye, are sometimes liable 
to be mistaken as to the nature of the pupil, as it 
appears like a black spot, instead of an opening. 
The aqueous, crystalline, and vitreous humors, 
together with the cornea, are transparent, and the 
rays of light pass through them to fall upon the 
retina. The office of the cornea and these humors, 
is to refract the rays of light in such proportion as 
to direct the image in the most favorable manner 
upon the retina. The retina receives the impression 
of the rays of light, which leave upon it the image 
of an object at which we look. The impression 
thus produced by the reflected light is transmitted 


THE NERVOUS SYSTEM. 


303 


by the optic nerve to the brain. This constitutes 
vision.* 

Visual Phenomena of Light. — The science of 
optics, however, treats not only of vision, but also 
of the properties and phenomena of light. To com¬ 
pletely comprehend the theory of vision, a knowl¬ 
edge of the anatomy of the eye, alone, is not 
sufficient. While it is not our purpose to enter 
minutely into the discussion of a subject which 
properly falls within the domain of natural philoso¬ 
phy, rather than of physiology, there are a few 
simple laws concerning the nature of light, by which, 

* Color-blindness. — “ Daltonism, or color-blindness, receives 
its name from the eminent English chemist, who described this in¬ 
firmity as it existed in his own case. It arises from an unnatural 
condition of the organs of vision which prevents the discrimination 
of certain colors. Some persons will mistake red for green; so 
that ripe cherries on a tree appear the same as the leaves; others 
recognize only black and white. Persons thus affected are some¬ 
times incapable of discriminating musical tones. The healthy eye 
ordinarily fails to discriminate between certain colors, blue and 
green especially, when viewed by artificial light. But even this 
may in a measure be overcome by training, so that an expert dealer 
in silk obtains a knowledge of the shades of blue, green, and 
violet, which is proof against the confusing influence of gaslight 
and tinted curtains. The eyes of persons who have much to do 
with colors are more liable to become overstrained than those 
dealing chiefly with rays of white light.” — Flint's Physiology (in 
part). 



304 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

if the reader briefly directs his attention, the phe¬ 
nomena of vision may be easily explained. Light is 
defined as that principle, or substance, which enables 
us to see any object from which it proceeds. If a 
luminous substance, as a burning candle, be carried 
into a dark room, the objects in the room become 
visible, because they reflect the light of the candle to 
our eyes. A ray is a single line of light, as it comes 
from a luminous body. A beam of light is a body 
of parallel rays. A pencil of light is a body of 
diverging or converging rays. Luminous bodies emit 
rays, or pencils of light, in every direction, so that 
the space through which they are visible is filled 
with them at every possible point. The sun, there¬ 
fore, illuminates every point of space within the 
whole solar system. A light, as that of a light¬ 
house which can be seen from the distance of ten 
miles in one direction, fills every point within a cir¬ 
cuit of ten miles from it with light. The rays of 
light move forward in straight lines from the lumin¬ 
ous body, and are never turned out of their course, 
except by some obstacle; yet when a ray of light 
passes obliquely from one transparent body into 
another of a different density , it leaves its linear di¬ 
rection , and is bent , or refracted , more or less , out of 
its former course . It is, therefore, by the refracting 
power of the aqueous humor and the crystalline lens 


THE NERVOUS SYSTEM. 


305 


of the eye, the most perfect of all optical apparatus, 
that the pencils of rays are so concentrated as to 
form a perfect picture of the object on the retina. 
The reader will now readily understand the phenom¬ 
ena of vision, by referring to the accompanying 
diagram. Rays of light reflected from the points A 
and B are slightly refracted inward entering the 
anterior chamber at C C , which contains the aqueous 
humor. Upon entering the crystalline lens D , they 
are still further bent, until at length these lines, meet¬ 
ing together at one point, form the focus E F. The 
highest point becomes lowest, and vice versa; or, in 
other words, the object is inverted; and what we call 
the upper end of a vertical object, is the lower end of 
its picture on 
the retina, and 
so the contrary. 

In the perfect 
eye, the point 
of meeting, or 
focus of the 
lines, is imme¬ 
diately on the retina, or inner lining of the eye. 

Should the posterior wall of the retina be too close 
to the crystalline lens, the lines would not meet; 
therefore, the vision would be blurred and confused, 
as on the line H. Should the retina be at the line G s 
20 








306 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the rays having come to a focus at E F will again 
diverge, and will thus result in an imperfect vision. 
In some conditions of the eyeball, as in short or far¬ 
sightedness, the convex portion of the eye, the 
cornea and the lens, which refract the light, are 
either too convex, or not sufficiently so, and thus the 
image is imperfectly reproduced on the retina. 
When the refraction of the rays of light is too great, 
as in over-convexity of the cornea, or the crystal¬ 
line lens, or of both, the image is formed a little 
in front of the retina, and persons thus aflected 
cannot see distinctly, except at a very short 
distance. This infirmity is called shortsighted¬ 
ness, or myopia . The defect is in a great 
measure obviated by the use of concave glasses, 
which scatter the luminous rays, and thus counter¬ 
balance the two strong refracting powers of the 
organ. When the different parts of the eye are not 
sufficiently convex, the image is formed beyond the 
retina, and thus only distant objects are distinctly 
seen. This defect is known as far-sightedness or 
presbyopia . It is usually a consequence of old age, 
and is remedied by wearing spectacles with convex 
glasses. Thus it is seen, that to view objects at a 
distance a less convex lens is needed than in the 
examination of articles very near the eye. The per¬ 
fect eye, however, is a wonderful piece of mechan- 


THE NERVOUS SYSTEM. 


307 


ism, possessing the singular and ingenious power of 
adaptation to widely different distances. This 
peculiar accommodation is effected by changes in 
the form of the lens. It has been proved that when 
the eye is turned from a distant to a near object, the 
antero-posterior diameter of the lens becomes elon¬ 
gated, and the anterior surface becomes more convex, 
while the opposite changes take place in turning the 
eye from a near to a distant object.* 

In conclusion, the optical apparatus of the eye 
comprises two solid substances—a horny and a 
glassy one — and two liquids, all four serving the 
purpose of lenses. There is no artificial contrivance 
which approaches it in excellence. 


* Close the left eye; with the right eye look steadily at the 
cross below, holding the page at a distance of about twelve 
inches. 



In this position both dot and cross will be seen distinctly. 
But if the book be slowly brought nearer to the face, the right 
eye being still fixed upon the cross, the dot will disappear dur¬ 
ing an instant, and as the book approaches the face, becomes 
visible again. Now, during the instant that the dot vanished out 
of sight, the image of the dot was on the blind spot of the retina — 
that is on the region of the retina where the optic nerve enters 
the choroid. 



308 ANATOMY, PHYSIOLOGY, AND HYGIENE 


HEARING. 

The Ear, the organ of hearing, is probably the 
most complicated in the body, and, next to sight, 
the most important. It is composed of three parts: 



THE EAR— TRANSVERSE SECTION THROUGH THE SIDE WALLS 

OP THE SKULL. 


OE Outer Ear. 

ET External Tube. 

Ty Tympanic Membrane. 
D Drum or Tympanum. 
Eu Eustachian Tube. 


M Hammer. 

I Anvil. 

va, ha, vpa Semicircular Canals. 

Coc Cochlea. 

AN Auditory Nerve. 


1st. The external ear . 2d. The tympanum, or mid¬ 
dle ear . 3d. The labyrinth , or internal ear. The 

external ear consists of two parts ; namely, the pinna , 






THE NERVOUS SYSTEM. 


309 


or wing, and the meatus auditorius (auditory canal). 
The pinna is the pavilion , or the prominent exter¬ 
nal part of the organ of hearing. It pre¬ 
sents many furrows and ridges, arising from 
the folds of the cartilage that forms it. The 
meatus auditorius is a partly cartilaginous and 
partly bony canal, about an inch in length, extending 
inward from the pinna to the membrana tympani 
(“ drum ” of the ear). It is lined with an extremely 
thin cuticle, and in the interior of the tube are found 
a number of short and rather stiff hairs, which 
obstruct the entrance of insects and other foreign 
substances. There are a number of small follicles 
beneath the cuticle, which secrete the ear wax. The 
membrana tympani is a thin semi-transparent mem¬ 
brane, about three-eighths of an inch in diameter, 
inserted in a groove of the meatus near its termina¬ 
tion. It is placed obliquely across the tube, having a 
concave surface toward the meatus, and a convex 
toward the tympanum. The tympanum is an irregu¬ 
lar bony cavity, bounded externally by the membrana 
tympani, internally by its inner wall, and in its cir¬ 
cumference by the petrous (stony) portion of the 
temporal bone and mastoid cells. The tympanum 
contains four small bones, named, respectively, the 
malleus , incus , stapes and orbicularis . There are 
several openings in the middle ear, among which is 


310 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the eustachian tube , a canal of communication extend¬ 
ing obliquely between the pharynx and the anterior 

circumference of the tym¬ 
panum. It is partly fibro¬ 
cartilaginous, and partly 
bony in structure. The 
labyrinth consists of a 
membranous and bony 
portion, the latter pre¬ 
senting a series of cavi¬ 
ties which are channeled 
through the substance of 
the petrous bone. It is di¬ 
vided into the vestibule , 
semicircular canals , and cochlea. The vestibule is sit¬ 
uated immediately within the inner wall of the tym¬ 
panum, and consists of a small, three-cornered cavity. 
The semicircular canals are three bony passages which 
communicate with the vestibule, into which two of 
them open at both extremities, and the third at one 
extremity. The cochlea forms the anterior portion of 
the labyrinth. It is about one and a half inches in 
length, and forms a bony and gradually tapering 
canal, which makes two and a half turns, spirally, 
around a central axis, called the modiolus. The 
membranous labyrinth is a perfect counterpart, with 
respect to form, of the bony vestibule, cochlea, and 




THE NERVOUS SYSTEM. 


311 


semi-circular canals. There are two small, elongated 

sac3 within this labyrinth, which are filled with water. 

The auditory nerve enters 

the temporal bone upon 

its internal surface, and 

divides into two branches 

at the bottom of the cavity 

of the internal ear. These 

branches, after radiating 

in all directions, finally 

. The Labyrinth—(ext. view), 

terminate upon the inner 

surface of the membrane in minute papillae, resem¬ 
bling those of the retina of the eye. 

The pinna, or that part of the external ear which 
projects from the head, performs the function of 
collecting sounds and reflecting them into the 
auditory canal. The drum of the ear (membrana 
tympani) not only moderates the intensity of sounds, 
but serves to facilitate their transmission to the parts 
interior. It has no opening in its healthy state, and 
it is so arranged that it may be relaxed or tightened. 
There being no opening in it, the apprehension which 
is often expressed, that bugs and insects may pene¬ 
trate within the deeper structures of the ear, and 
even to the brain, is without real cause; foreign 
bodies in the ear, of course, produce intense pain; 
but that is owing to the irritation of the exceedingly 



312 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

sensitive membrana tympani. The office of the 
eustachian tube is to admit air from the mouth into 
the tympanum, which renders the pressure on each 
side equal, thus keeping its membrane in a proper 
state of tension. Therefore, if the mouth is kept 
open while a cannon is discharged near by, the shock 
is lessened. 

Thus, the vibrations of air are collected by the 
external ear, and conducted through the auditory 
canal to the drum of the ear; from this membrane 
the vibrations pass along the chain of small bones to 
the internal ear; in the internal ear these are at 
once taken up by the fluid in the vestibule 
and transmitted to the remaining liquids in the 
various canals composing the labyrinth. The 
motion of the liquids causes the minute fibres and 
hair-like terminations of the auditory nerve, which 
are floating freely in the liquids, to vibrate; and their 
vibrations are carried by the auditory nerve to the 
brain. 

6. HYGIENE AND DISORDERS OF ORGANS 
OF SENSE. 

The Organs of Sense are the ways, or machines, 
by which the mind, which acts within the man, gets all 
its knowledge of the world. Without these nothing 


THE NERVOUS SYSTEM. 


313 


could bo known of all the interesting and beautiful 
things about us. How dark and lonely would life 
be I Since so much depends upon these organs it 
certainly behooves us to look to the proper care of 
them. For this reason we think it wise to consider 
here some of the most important rules for their 
health. 

Hygiene of the Sense of Touch. — Much of 
pleasure or of pain may result from the condition 
of this organ. 

(1) The Condition of the Epidermis Determines 
the Character of the Impression made upon the 
Nerves .— When the cuticle has become thick and 
hard, like horn, as on the inside of the mason’s 
hand, it enables him to ply his tools without much 
suffering, because the thickened cuticle diminishes 
the impressions made upon the nerves. 

When the cuticle is very thin and delicate, as on 
the hand of the lady who is unaccustomed to manual 
labor, let her pursue some manual employment 
for several hours, and the extreme tenuity, or thin¬ 
ness of the cuticle, will not protect the nerves and 
parts below from becoming irritated and inflamed. 

When the cuticle is removed by blistering or 
abrasion, the pain indicates that the naked nerves 


314 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

are too powerfully stimulated by the contact of 
external bodies. When the cuticle is coated with 
impurities, blended with the secretion from the 
oil-glands, the sensibility of the skin is lessened. 

(2) Habit has much to do with the Nerves of 
Touch as to the Acuteness of Impression .— By long 
practice the blind girl is enabled to distinguish very 
readily the little points and angles of the raised 
letters and other characters on the page of the book 
for the blind. So acute has this sense become by 
training that the blind and deaf person is able to 
understand what is spoken to her by putting her 
finger-tip upon the lips of the person speaking. 

Hygiene of the Sense of Taste.— Some one has 
said: “ The tastes of men present the most singular 
diversities, partly the result of necessity and partly 
of habit or education.” 

(1) Taste is Largely Dependent upon Habit .— 
Not infrequently those articles which at first were 
disgusting become highly agreeable by persevering 
in the use of them, as in learning to chew tobacco 
and medicinal roots. 

(2) The /Sense of Taste Becomes Impaired by the 
Immoderate use of Stimulants and Condiments .— 
These indulgences lessen the sensibility of the nerves. 


THE NERVOUS SYSTEM. 


315 


In children this sense is usually acute, and their 
preference is for food of the mildest character. 


Hygiene of the Sense of Smell. — This sense, like 
all the others, is for benefit and pleasure. It aids in 
selecting food and gives satisfaction in the inhaling of 
agreeable odors. 

(1) The Sense of Smell may he Improved by 
Use .— Thus the Indian can easily distinguish different 
tribes and different persons of the same tribe by the 
odor of their bodies. Next to touch, smell is of 
great importance to the blind. 

(2) Smell Requires for Acuteness that the Brain 
and Olfactory Nerve , also the Lining Membrane of 
the Nose , be in a Healthy Condition .— Any influence 
that diminishes the sensibilty of the nerves, thickens 
the membrane or renders it dry, impairs this sense. 
The mucous membrane of the nasal passages is the 
seat of a chronic catarrh. This affection is difficult 
of removal, as remedial agents cannot easily be intro¬ 
duced into the windings of these passages. Snuff 
and many other articles used for catarrh produce 
more disease than they remove. 

Hygiene of the Sense of Sight. — The appreciation 
of color, form, size, distances, etc., is due to the 


316 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

sense of sight almost entirely. As to value some are 
disposed to rank it first among the senses. 

(1) The Eye should he Used and should be Rested .— 
If we look intently at an object for a long time, thp 
eye becomes wearied, and the power of vision dimin¬ 
ished. The observance of this rule is particularly 
needful to those whose eyes are weak, and predis¬ 
posed to inflammation. On the contrary, if the eye 
is not called into action, its functions are enfeebled. 

(2) Light should fall upon the Object and not into 
the Eye. — The position of the body should be such 
that the light will come from the left side or the rear; 
never from the front . 

(3) “ Sudden Transitions of Light should be 
Avoided .—The iris enlarges or contracts, as the 
light that falls upon the eye is faint or strong; 
but the change is not instantaneous.” 

(4) The Direction of the Vision should receive 
Attention .—If the eye is turned obliquely for a 
long time in viewing objects, it may produce an 
unnatural contraction of the muscle called into action. 
This contraction of the muscle is termed strabismus , 
or cross-eye. The practice of imitating the appear¬ 
ance of a person thus affected, is injudicious, as the 


THE NERVOUS SYSTEM. 


317 


imitation, designed to be temporary, may become 
permanent. 

The vision of a “ cross-eye ” is always defective. 
In general, only one eye is called into action, in 
viewing the object to which the mind is directed. 
This defect can be remedied by a surgical operation, 
which also corrects the position of the eye. 

(5) Particles of Dust , etc., which may get into the 
Eye, should be Removed at Once .— Rubbing only irri¬ 
tates and increases the sensitiveness. If the eye be 
shut for a few-moments that the tears may accumulate 
and the upper lid then lifted, the foreign body will 
very likely be washed away. 

(6) The Eye should be Bathed with hot Water. — 
This should be done when the eye is known to be 
weak or becomes weary, and is best performed in 
the following manner. 

Set an ordinary tumbler or drinking goblet in a 
plate. Put a teaspoonful of table salt in the glass. 
Now fill the goblet with hot water until it is “ brim- 
full.” See that the water is as hot as it can be borne. 
Now place the head over the tumbler, letting the eye 
down into the water till the head rests upon the 
glass. As the water cools pour in more hot water, 
keeping the temperature up to the highest point 
endurable. 


318 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Do this for twenty to thirty minutes each evening 
for several days. Great benefit will result. 

Hygiene of tlie Sense of Hearing.— The delicacy 
of the ear is such that it must have very great care. 
Its location far within the large temporal bone of the 
skull is nature’s precaution with regard to this organ. 

(1) Avoid Boxing the Ear .— Entire deafness 
may be produced by a fall or a heavy blow over the 
ear. There are cases on record of children having 
their hearing permanently injured by such treatment. 

(2) Do Not Remove the Wax which is secreted at 
the entrance to the canal of the external ear. Nature 
attends to the cleaning of the ear. The wax secreted 
keeps out foreign bodies and in time dries up and 
falls out of its own accord, leaving the ear clean and 
unharmed. In health the ear is never dirty. The 
canal leading into the drum of the ear is here 
referred to. If we attempt to wash it we either 
make it dirty by spreading the wax and dust about 
on the walls of the canal or we irritate and injure it. 
One of the most hurtful things is to introduce the 
corner of the towel, screwed up, and twist it around. 

(3) Hearing May be Impaired by Obstruction of 
the Eustachian Tube .— The closure of this canal 


THE NERVOUS SYSTEM. 


319 


diminishes the vibratory character of the air within 
the tympanum, in the same manner as closing the 
opening in the side of a drum. For the same reason, 
enlarged tonsils, inflammation and ulceration of the 
fauces and nasal passages during and subsequent to 
an attack of scarlet fever, and the inflammation 
attending the “sore throat” in colds, are common 
causes of this obstruction. 

The treatment of such cases of defective hearing, 
is to have the tonsils, if enlarged, removed by a 
surgeon ; for the inflammation and the thickening of 
the parts remedial means should be applied, directed 
by a skillful physician. The nostrums for the cure 
of deafness are generally of an oleaginous character, 
and may be beneficial in cases of defective hearing 
caused by an accumulation of wax upon the drum of 
the ear, but in this respect they are no better than 
the ordinary animal oils. 

(4) Direct Draughts into the Ear Should be 
Avoided .— Earache in children is often caused by 
this thing. And deafness has been known to result 
from letting rain and sleet into the ear. 

7. THE MIND. 

We have now seen that man possesses a passive 
framework composed of bones, which form the levers 


320 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

by which he accomplishes his movements. These 
levers are' acted upon by the muscles, which there¬ 
by become the proper organs of motion. These, in 
turn, are controlled to a greater or less extent by 
the nervous system. The bones, muscles, sensory 
organs and nervous system have very properly been 
called the “Animal Apparatus of Life; ” they are 
found in all the higher animals. 

Now, there is another function apparent in the 
human body, in virtue of which a constant building- 
up or repairing of these essentials of animal life is 
going on within the body, which is called for by 
the continuous wear and tear of bones, muscles 
and blood. This function is performed by organs 
which (1) make blood such as the alimentary canal 
and the lymphatics; (2) keep the blood in circu¬ 
lation, as the heart; and (3) maintain it in a pure 
state, as the lungs. These organs have been com¬ 
prised under the head of “ Organic Apparatus of 
Life,” and are also influenced by the nervous system. 

The animal apparatus of life intimately con¬ 
nects man with the higher animals; the organic 
apparatus of life with the vegetable kingdom. 

Many of the Higher Species of animals have been 
greatly changed by domestication. Their ferocious 
habits have been modified, their instincts improved, 


THE NERVOUS SYSTEM. 


321 


their intelligence developed; but in spite of all this, 
domesticated races, when left to themselves, after a 
few generations return to their original wildness. 
And the superiority of training which an individual 
animal may have received never benefits his species 
or race. 

With the Human Being it is very different. Man 
is gifted not only with an unlimited capacity for 
mental accomplishment, but also with a never-ending 
desire to acquire new mental attainments. And in¬ 
dividuals of ability and talent seldom fail to benefit 
their race. From these gifts spring the eagerness 
of the hnman being for education . Education 
consists chiefly in repressing the lower habits of 
human nature, and in developing its nobler qual¬ 
ities. 

Beyond all this there exists yet something more 
elevated, though more difficult to analyze, viz.: the 
faculty which enables us to conceive the idea of the 
infinite and our relations to the infinite, by which 
we possess aspirations after Truth , Goodness , Right , 
and Beauty . 

If the Capacity for, and Desire after, mental ac¬ 
complishment, referred to above, be expressed by 


21 


322 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the term Mind , we must recognize (a) that the mind 
is greatly dependent upon the condition and the 
state of health of the body, and (b) that the body, in 
turn, is easily affected by the mind. There are 
many familiar facts to testify to this, among which 
may be mentioned as proofs of a : (1) The necessity 
of proper food to nourish the brain: that is, of pure 
blood with an abundance of oxygen. Wherever 
this is wanting, mental activity decreases. (2) The 
effect of local affections of the brain, as when a per¬ 
son has received a severe blow on the head. (3) The 
effect of intoxication, or (4) of poison, or (5) of 
fever, or other bodily disorder. And among the 
numerous proofs of b we have: (1) The well-known 
effects of anxiety, fear or joy on the body. (2) 
The injurious effect of mental depression on bodily 
functions. (3) The self-restraint exerted by the 
body in obedience to efforts of the will. 

Attention.— Every individual has a certain capac¬ 
ity of concentrating his faculties upon a task which 
he wishes to perform. Thus, he may wish to acquire 
knowledge, to repress his anger, to control his 
habits, or to observe strict honesty in his dealings 
with others; but for any and all of these activities 
he needs a certain power of will. This power of 
will he must bring to bear upon his faculties in 


THE NERVOUS SYSTEM. 


323 


order to be successful. If all his faculties are di¬ 
rected upon any one activity at a time, as for 
example, upon the acquisition of mathematics, he 
nearly excludes them from any other activity, and 
is then said to be attentive . Attention, therefore, is 
the concentration by the power of will of all the 
faculties upon some one activity to the exclusion of 
others. Thus, a young person who is bent over his 
slate, concentrating all his activities upon an arith¬ 
metical problem, is almost unaware of what is going 
on around him. He will deprive the sensory 
organs of nearly all their faculties, which are now 
spent in inward attention. On the other hand, a 
countryman visiting a large town for the first time, 
does not follow any particular train of thought, but 
has his senses busily engaged by the novelties with 
whieh he is impressed at every step. His will does 
not direct his faculties to any special activity; they 
are devoted to his sensory organs, and, consequently, 
his attention is wholly outward. 

Perception.— A sleeping person may unconsciously 
start at a loud noise, and then resume his former 
state of sleep. His sensation was correct; he was 
conscious of it, but he had no distinct perception 
regarding the source or nature of the sound, be¬ 
cause he bestowed no attention upon it. Or, if the 


324 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

young student, referred to above, had been less ab¬ 
sorbed by his mathematical problem, he might have 
unconsciously heard cries outside of his room, and 
yet not have had a distinct perception of them ; and 
having finished his task, and hearing the crie3 again, 
this time with his full attention directed toward 
them, he may dimly remember to have heard them 
before. While, then, a sensation is an impression 
upon a conscious state of mind, a 'perception is an 
impression upon a conscious state of mind accom¬ 
panied by attention; or, perception = sensation + 
attention. From the preceding it will be clear that 
a person having heard a loud report at a distance 
repeated several times, in speaking about it will, 
with perfect propriety, describe the sensation which 
the sound produced in himself , and which, as yet, 
he may attribute to the roaring of cannon, or thun¬ 
der, or to an explosion. Now, let him arrive on the 
spot from whence the noise proceeded. Suppose it 
to have been due to the practice of artillery. He 
will then perceive the source and the nature of the 
report, and thus obtain a distinct perception of the 
cannon, which he may afterwards describe. He has 
now learned something outside of himself , and his 
mind is no longer engrossed with its own sensation. 

Ideas.— After his return, the same person can 
accurately picture the cannon and represent to him- 


THE NERVOUS SYSTEM. 


325 


self its effect; that is he has retained a mental repre¬ 
sentation or idea of the object and its effect. This 
idea he can afterwards reproduce in audible or visi¬ 
ble signs — words; or, if he is an artist, he can 
paint it. An idea is the mental representation of 
an object; it calls for a higher mental activity than 
perception. 

A succession of ideas gives rise to thought . The 
conscious mind is incessantly engaged in thought. 
We might continue, and treat of the laws of 
thought, emotion, habit, will, sleep, and dreams, 
but the limits of the present volume have now been 
attained. For further information, the younor 
student should peruse works oil psychology. 


326 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

REVIEW QUESTIONS. 

1. What is the organ of Touch? 

2. What can you say of its fitness? 

3. What is the difference between touch and pain? 

4. Where is the touch most delicate? 

5. Of what use is the epidermis ? 

6. What are the terminations of the nerves of touch? 

7. What is the organ of Taste? 

8. Does the tongue give more than the sense of taste? What? 

9. To what other sense is that of taste allied? 

10. Describe the organ of Smelll 

11. What is the use of the turbinated bones? 

12. How does the olfactory nerve terminate? 

13. How do we smell? 

14. Compare acuteness of this sense in man with that of animals. 

15. Name the parts of the organ of sight. 

16. Draw a cross section of the eyeball. 

17. Describe each of its parts. 

18. What is myopia ? presbyopia ? hyopia ? 

19. Draw a vertical section of the ear. 

20. Name parts and tell location. 


21. Discuss the 

organ of Touch. 

care 

of 

and 

give 

rules 

of 

hygiene for 

the 

22. Discuss the 

organ of Taste. 

care 

of 

and 

give 

rules 

of 

hygiene 

for 

the 

23. Discuss the 

organ of Smell. 

care 

of 

and give 

rules 

of 

hygiene 

for 

the 

24. Discuss the 

organ of Sight. 

care 

of 

and 

give 

rules 

of 

hygiene 

for 

the 

25. Discuss the 

care 

of 

and 

give 

rules 

of 

hygiene 

for 

the 


organ of Hearing. 

26. What is Attention? Perception? 


THE NERVOUS SYSTEM 


327 


BLACKBOARD OUTLINE. 

THE NERVOUS SYSTEM. 


I. Structure. 

1. Kinds of matter. 

2. Divisions. 

II. Organs of the Nervous System. 

1. The Brain. 

The Cerebrum. 

The Cerebellum. 

The Medulla Oblongata. 

2. The Spinal Cord. 

3. The Nerves. 

The Cranial Nerves. 

The Spinal Nerves. 

4. The Sympathetic System. 

Ganglia. 

Nerves. 

III. Functions of the Nervous System. 

1. The Brain. 

2. The Spinal Cord. 

Decussation of Fibres. 

Roots of Nerves. 

Reflex Action. 

3. The Nerves. 

Motor and Sensor Nerves. 

4. The Sympathetic System. 

IV. Hygiene and Disorders of the Nervons System. 

V. Organs of Sense. 

1. Touch. 

2. Taste. 

3. (Smell. 

4. Sight. 

5. Hearing. 

VI. Hygiene and Disorders of the Organs of Sense. 



IX. 


HYGIENE-ALCOHOL-STIMULANTS - 
NARCOTICS-THEIR EFFECTS. 


No vice is mars hereditary than intemperance ,— TJr, Yellow- 
Ices. 

There is no such thing as a temperate use of spirits, In any 
quantity they are an enemy to the human constitution. Their 
influence upon the physical organs is unfavorable to health, 
They produce weakness, not strength; sickness, not health; 
death, not life, — Ur, Rlden, 

Ifice is a monster of so frightful mien, 

Rs to be hated needs but to be seen ; 

But seen too oft, familiar with her face, 

life first endure, then pity, then embrace, — Pope, 

( 329 ) 





IX. Hygiene — Alcohol— Stimulants—Nar¬ 
cotics—Their Effects. 

1. ALCOHOL. 

Alcohol, one of the most active stimulants, not only 
from its effects but from its wide occurrence, being 
found in nearly all intoxicating drinks, leads every 
other drug in its far-reaching influence for mischief 
and evil. Were the thousands of ruined homes, the 
untold numbers of blasted lives, the sorrows, sins, 
numberless crimes, murders, and deaths, that follow 
yearly in the train of this fell destroyer, brought 
into panoramic review before us, what a hell-born 
picture it would be 1 

Properties. — Alcohol is a clear, watery-like, vola¬ 
tile fluid, having a hot, pungent taste and a pene¬ 
trating odor. It burns with a pale blue flame and 
intense heat. It is specifically lighter than water, 
having a specific gravity of about 0.8, which means 
that a given volume of it weighs only about as 
much as the same volume of pure water. Its boil- 

( 331 ) 


332 ANATOMY, PHYSIOLOGY, AND HYGIENE# 

ing point is lower than that of water, being about 
175° Fahrenheit (that of water being 212° F.). 

It has a strong attraction for water, and mixes 
with it in all proportions. What is known as the 
ordinary alcohol of commerce is pure alcohol mixed 
with water. 

A drop of it placed upon the skin produces the 
sensation of cold, which is due to its rapid evapora¬ 
tion. 

Manufacture. — Alcohol can be made from any 
substance containing sugar. This fact is readily 
seen from comparing the two classes of sugars: 
Sucroses C^H^On and glucoses C 6 H 12 0 6 with methyl 
hydrate , CH 3 OH and ethyl hydrate C 2 H 6 ON, which 
is common alcohol , each compound being a union 
of hydrogen, oxygen, and carbon. 

Uses. — Since it does not freeze, it is used in 
thermometers. It is also used in levels, and finds 
a wide use in the arts and sciences, especially in 
the science of medicine. There are over a dozen 
different kinds of alcohol, but we shall deal with 
what is termed common alcohol , called also spirits 
of wine . 

Alcohol is used in the arts for many useful pur¬ 
poses. On account of its great capacity of dissolv- 


HYGIENE. 


333 


ing substances, it is used as a solvent of rosins, 
cements, pharmaceutical preparations, and for the 
manufacture of perfumes and essential oils. 

On account of its capacity for preserving vege¬ 
table and animal fibres, it is used to preserve ana¬ 
tomical specimens and articles of food. 

On account of its stimulating powers it is used by 
physicians in small quantities greatly diluted with 
water, to promote or stimulate the action of organs 
such as the heart or stomach. But instead of using 
pure alcohol diluted with water, pure light wines are 
usually recommended by physicians on account of 
their flavor, as all such wines contain a small por¬ 
tion of alcohol. Its use in counteracting the effects 
of snake-bite are well known. 

Effects. — The General Effects of Alcohol are 
insidious, serious, and saddening. “ The evil that 
men do lives after them, ,, is only too true in the 
general effects of the use of alcoholic drinks. Beer, 
wine, liquors and whatever other names the differ¬ 
ent beverages may bear that are used by mankind 
on account of the effects which the smaller or 
greater percentage of alcohol they contain may 
exert, are known for their general effects upon the 
human system as well as for the certain special 
effects which we shall describe hereafter. Most 


334 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


people use them as stimulants, some as medicine, 
and some — the unfortunate victims of a slavish 
desire — as a means of reaching an early grave. 

The Special Effects of Alcohol are both of a 
stimulant and a narcotic . As a stimulant, it excites 
the brain and nerves, increases the circulation of the 
blood, and intoxicates, while as a narcotic it blunts 
the powers of the brain and nerves, and produces 
stupor, and finally, death. Since alcohol contains no 
nitrogen, it lacks one of the chief elements of food, 
and consequently will not sustain life. “ Alcohol has 
no iron nor salts for the blood; no gluten, phos¬ 
phorus, nor lime for the bones; and no albumen, or 
substance which is the basis of every living organ¬ 
ism. ”— Dr. Lees. Hence, it cannot be termed a 
food. Tests in the army, navy and Arctic explora¬ 
tion* have definitely proven the above position. 

Neither will alcohol allay thirst, and for the foliow- 


♦ The Arctic explorer, Dr. Rae, states that he found entire 
avoidance of alcohol necessary in the far North. The moment a 
man had swallowed a drink of spirits, it was certain that his day’s 
work was nearly at an end. “ It was absolutely necessary that 
the rule of total abstinence should be rigidly enforced, if we 
would accomplish our day’s task. Any use of liquor, as a bev¬ 
erage, when we had work on hand, in that terrific cold, was out of 
the question.” 



HYGIENE. 


335 


ing reasons: Alcohol has great attraction for water, 
and when swallowed draws the water to itself, thus 
depriving the tissues of the body of that most neces¬ 
sary inorganic food. Again, alcohol causes a rush of 
blood to the skin, when a sensation of heat is felt 
upon the surface of the body. However, the sensa¬ 
tion of heat is like beauty, “ only skin deep,” as the 
heat of the system has really been diminished rather 
than increased, because when the blood is upon the 
surface, it parts with its heat more readily. The 
deception is similar to the case of the ostrich, which 
imagines himself concealed when only his head is 
hidden. 

Let us discuss this subject as to the effects upon the 
individual organs and parts of the human system. 

(1.) On the Heart .— The reason why small quan¬ 
tities of alcohol which are greatly diluted with water 
stimulate the system, is due to the fact that the alco¬ 
hol enters the circulation, permeates the body and 
is burnt up or oxidized within the system, yielding, 
as a result of this combustion, heat and vital force to 
the tissues of the body. Given the number of heart¬ 
beats at 100,000 per day of twenty-four hours, an 
ounce of pure alcohol will raise this to 104,000, 
which increased beating overworks the heart. 
Since, then, the circulation is stimulated, it follows 


336 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

that the action of the heart is invigorated; the struc¬ 
tural part of this organ, however, suffers no change. 
Larger doses of “ stimulants,” however, exert a 
depressing influence upon the heart, rendering it 
flabby, dilated, and sometimes fatty, so as to reduce 
its action; they lower the temperature of the body 
and generally retard the action of the cells. In the 
language of a medical author — 

“ The agreeable excitement at first caused by such 
doses of alcohol is succeeded by a reaction, char¬ 
acterized by lassitude and drowsiness, the latter 
condition usually lasting longer than the previous 
one of exhilaration.” 

In many diseases it is desirable to animate the 
circulatory system to greater action ; this is especially 
the case with fever patients; they can stand consider¬ 
able quantities of alcohol without intoxicating effects ; 
and as alcohol lowers the temperature of the body, 
the fever-heat is lowered also, owing to the use of 
alcohol, and thereby improves the condition of the 
patient. 

Then the effects of alcohol upon the heart may be 
summed up m the following statements: — 

(a.) It causes a softening of the muscles of the 
heart and a fatty degeneration, thus clogging the 
workings of this vital organ. 


HYGIENE. 


337 


(6.) It overworks the heart. 

(c.) Oftentimes it renders the heart weak and 
flabby. 

(e?.) It causes an enlargement, or dilation of its 
parts. 

(e.) There is a consequent effect of drowsiness and 
lassitude. 

(/*.) Its general effect upon the heart is to destroy 
its strength and usefulness. 

(2.) On the Lungs .—Persons who are addicted 
to excessive drinking, and especially those “chronic” 
drinkers who are predisposed to lung troubles, are 
subject to pneumonia and to consumption. In these 
disorders, the trouble is aggravated by a diseased 
condition of the blood, brought about by the use of 
alcohol. As the diseased blood comes to the capil¬ 
laries of the lungs, this impairs the lungs themselves, 
which adds to the impurity of the circulating fluid. 
It also tends to paralyze the capillaries of the lungs, 
while it gives the breath a most disagreeable odor. 
Hence, it is learned that alcohol has the following 
effects upon the lungs: — 

(a.) It makes the blood impure, thus increasing 
the work of the lungs. 

(b.) It paralyzes the blood-vessels. 


22 


338 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

(c.) It weakens the various lung tissues. 

(d.) Alcohol vitiates the breath. 

(3.) On the Stomach .— The immoderate use of 
alcohol may produce chronic inflammation, conges¬ 
tion or catarrh of the stomach and the duodenum. 
The inner coat of the stomach is greatly changed by 
the excessive use of alcohol, and loses its capacity 
for secretion and absorption. 

To appreciate the effect of alcohol upon the mu¬ 
cous lining of the stomach, take a mouthful of the 
liquor into your mouth. Since it burns your mouth, 
how much more so the very delicate stomach lining. 
In a natural state, the stomach lining is a beautiful 
pink, but alcohol destroys this condition and covers 
it with ulcers and sores. Read what Dr. Beaumont 
learned of these effects by experiments upon Alexis 
St. Martin: “ The free use of ardent spirits, wine, 
beer, or any of the intoxicating liquors, when con¬ 
tinued for some days constantly, produced a state of 
inflammation and ulceration in the lining membrane, 
and change in the gastric juice.” Not only does it 
harden the tissue of the stomach lining, destroy some 
of the little glands, and impair the others, but it 
affects the mucous, making it thick, and precipitates 
the pepsin, which delays digestion. As a result of 
the quickened action of the stomach, the effect upon 


HYGIENE. 


339 


its tissue and fluids, and the derangement of its 
organs, digestion in the stomach is materially im¬ 
paired and the nutrition of the body greatly weakened 
and lessened, which will finally lead to a total collapse 
of the digestive system. Hence, to recapitulate: — 

(a.) Alcohol produces chronic inflammation of the 
stomach. 

( b .) Injures the mucous lining by hardening the 
tissue. 

(c.) It destroys some of the small glands and 
impairs the others. < 

(cZ.) It precipitates the pepsin of the gastric juice, 
thus retarding digestion. 

(e.) It thickens the mucous of the stomach, 

(/.) The action of the stomach is at first quick¬ 
ened by the presence of alcohol, and then retarded. 

(4.) On the Liver .— A commonly occurring dis¬ 
ease of the liver, known as cirrhosis of the liver (or 
gin-drinker’s liver), in which this organ becomes 
hardened and shrunken, arises from an abuse of 
alcoholic drinks, more especially of spirits undiluted 
with water, which reach the liver through the blood 
by the portal vein. Most cases of this kind, when 
once established, terminate in death. Through the 


340 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

effects of alcohol, the vessels of the liver are over¬ 
filled, which affects the liver end of digestion by pro¬ 
ducing a fatty enlargement. This enlargement is 
followed by a lessening of the cells which produce 
the bile, and thus interferes with the proper passage 
of the blood through this necessary and important 
organ. Again the tissue of the liver may be greatly 
enlarged by the presence of alcohol in that organ. It 
has been recorded of a drunkard that his liver was 
found to weigh fifty pounds, while a healthy one 
weighs only a few pounds. Again, alcohol stimulates 
the liver to over-action, which results later in its 
inability to secrete the proper amount of bile. 

In substance, then, the effects of alcohol upon the 
liver may be :— 

( a .) It produces a hardened condition of its tissue. 

(b.) It enlarges the organ. 

(c.) It compresses and lessens the cells for pro¬ 
ducing bile. 

( d .) It stimulates the liver to over-action, thus 
reducing the bile supply. 

(e.) It weakens and destroys the usefulness of this 
organ of digestion. 

(5.) On the Blood and Blood-vessels .—Whatever 
impairs the functions of the stomach is certain also to 


HYGIENE. 


341 


impair the proper condition of the blood and the 
nutrition of the body ; so that an habitual excess of 
alcohol cannot but deteriorate the “life-giving” 
fluid. A too frequent use of alcohol tends to 
change the coats of the blood-vessels by unduly 
dilating them, as their muscles become weakened. 
Both changes combined — that of the blood and the 
vessels that circulate it through the body — together 
with the injurious influence which large doses of 
alcohol have upon the nerves, have a baneful effect 
upon the entire system. It is interesting to know 
how alcohol reaches the blood. From the stomach, 
it is immediately absorbed into the blood, while 
some of it passes on into the intestines to pass to the 
blood by the lacteals. When in the blood, alcohol 
tends both to thin and coagulate the blood, owing to 
the amount of the drug present. It has a deadening 
effect upon the corpuscles, destroying their power 
to carry oxygen or carbonic acid gas; hence it pre¬ 
vents combustion, which prevents the purification 
that ought to take place. This effect subsequently 
impoverishes the blood, producing skin disorders of a 
dangerous nature. The fact of alcohol’s hastening the 
circulation was discussed in the topic— On the Heart. 

This topic will be concluded with the statement 
that alcohol exercises a paralyzing influence upon the 
nerves controlling the muscular fibres of the arteries. 


342 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Therefore, the effects of alcohol upon the blood and 
blood-vessels are:— 

(a.) It thins or coagulates the blood, according to 
the amount of alcohol. 

( b .) It hastens the circulation, thus weakening it. 

(c.) It prevents combustion. 

( d .) It impairs and destroys the corpuscles, thus 
affecting their power of transporting oxygen and 
carbonic acid gas. 

(e.) Alcohol weakens the arterial muscles by 
affecting the nerves governing them. 

(/.) It produces skin disorders of dangerous kinds 
by vitiating the blood. 

(6.) On the Brain and Nervous By stem .—A 
large amount of alcohol acts on the nerves and nerve 
centers as a poison. In the latter stage of drunken¬ 
ness or debauch it may cause insensibility to such a 
degree as to produce death. We quote from a 
learned writer on the subject: “In slight cases of 
intoxication prolonged drowsiness may be the chief 
symptom, but in the more severe forms the patient is 
quite insensible; the power of motion is in complete 
abeyance; the breathing is loud and deep; the face 
b usually pale; the pupils are generally dilated; the 


HYGIENE. 


343 


pulse is slow and labored; the skin feels cold and 
clammy ; the temperature is low.” 

By its hastening influence upon the blood-vessels 
of the brain, these are so enlarged that they produce 
a compression, which results in epilepsy or apoplexy. 
The presence of alcohol in the brain will harden the 
tissue of that organ, which is mainly albumen. As a 
test of this, pour alcohol over the white of an egg, 
and notice the effect in a short time. The albumen 
coagulates. Why not the brain substance, then? 
Alcohol seems to seek the brain, as more of it is found 
there than in any other organ. This presence of 
alcohol certainly paralyzes the nerve-centers of this 
vital organ, leaving an enfeebled reason, a lessened 
and weakened will-power, with a consequent loss of 
self-control, all of which lead to temporary, if not 
permanent, insanity. Alcohol destroys the nerve fibre 
of the brain; if not, it diminishes its sensibility and 
unfits it for proper use. 

The effect of alcohol upon the morals is awful. 
“ All delicacy, courtesy and self-respect are gone ; the 
sense of justice and of right is faint or quite extinct; 
there is no vice into which the victim of drunkenness 
does not easily slide, and no crime from which he can 
be expected to refrain. Between this condition and 
insanity there is but a single step.” 

“ If by reducing the balancing power of the vessels 


344 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

which regulate the supply of the blood to my brain, 
I permit a more rapid current of blood to feed my 
brain, I may for a time think more rapidly, and 
express myself with more apparent energy. It is 
clear, however, that under such circumstances I do 
but exhaust more quickly, require to be wound up 
more frequently, and wear out more speedily.” — 
Dr. Dichardson. 

There are times, when men have seemed to be 
brighter and more brilliant when under the influence 
of liquor; but it is an abnormal condition.* The 
various effects of alcohol upon the brain and nerves 
are: — 

(a.) It causes apoplexy or epilepsy by confusing 
the brain. 

( b .) It weakens the will and deadens the feel¬ 
ings. 


* In the normal state of a man's mind, all the faculties, the 
imagination, the judgment, the memory, the association of ideas, 
are regulated by another superior faculty, viz., the attention. The 
attention of the will is the man himself; it is the ego which, being 
in the full possession of the resources of which it disposes, takes 
them where it will, when it will, to do whatever it pleases. Now 
in drunkenness, even at the very beginning, the will and the 
attention have disappeared. Nothing is left but the imagination 
and the memory, which, left to themselves, without regulation and 
without guides, produce the most irrational results.” — Charles 
Richet. 



HYGIENE. 


345 


(c.) It hardens the brain tissue, producing dullness, 
insensibility and insanity. 

( d .) It destroys the nerve fibre of the brain. 

(e.) It temporarily stimulates and finally depresses 
this organ. 

(/.) It will at last destroy man, body and soul. 


2. WINE, RUM, BRANDY, ARRACK AND 
OTHER SPIRITUOUS LIQUORS. 

Stimulants.— Wine is the fermented juice of the 
grape. One thousand parts of it contain, as a rule, 
about 900 parts of water, 80 parts of alcohol, and 20 
parts of various bodies, such as acids and ethers. 
The Chinese forbade the use of wine and the culti¬ 
vation of the grape. 

Wines containing a large portion of carbonic acid 
gas are called “ sparkling ” wines; such as contain a 
great deal of “ acid” are called “ sour” wines; those 
containing much free sugar, “sweet” wines, and 
those containing a large quantity of alcohol, 
“ strong ” or “ heavy ” wines. 

Red wines contain from about 10 to 15 per cent 
of alcohol, which means that 100 volumes of such 
wines contain from 10 to 15 like volumes of alcohol. 
White wines contain less. 


346 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


The home-made wines from currants, elderberries, 
gooseberries, blackberries etc., contain a very small 
per cent of alcohol. 

Rum is the product of the distillation of fermented 
sugar cane, and is fully one-half alcohol. 

Cider is make from apples, and contains about 7 
per cent alcohol. 

Brandy or Cognac is a result of the distillation of 
strong wines, and has as much alcohol as rum. 

Arrack is obtained by distilling rice or palm juice 
and is much used as a drink by the Africans. 

Whisky is a product of the distillation of wheat, 
rye or corn. 

Liquors , in general, are highly flavored liquids 
containing a large percentage of alcohol mixed with 
large quantities of sugar. 

Beer , Ale, and Porter contain less alcohol than 
wine; generally not over five per cent, and are made 
from grain. 

Coffee and Tea are mild stimulants, yet they 
should not be taken in strong doses, nor in large 
quantities. Their effect seems to be to assist diges¬ 
tion; they are therefore generally taken after meals. 


HYGIENE. 


347 


But their intemperate use causes indigestion, nervous¬ 
ness, and other troubles. 

Chocolate and Cocoa are not so stimulating as 

© 

coffee and tea, but are much more nutritious. 

3. TOBACCO. 

History and Properties.— Tobacco is a native of 
America, from where it was taken to Europe. 

This plant, of the genus nicotiana , is a broad-leaved 
annual, growing five or six feet high, and cultivated 
as far north as Mason and Dixon’s line. 

The leaves are cut, dried, and cured, when they 
are made into various forms for use, too well known 
to need description. The leaves have a sharp, bitter 
taste, and are of a poisonous, narcotic nature, which 
is due to a volatile alkaloid called nicotine , from Jean 
Nicot, a Frenchman who first introduced it into 
France. 

Uses and Effects.— Nicotine is a dark-colored, 
deadly poison, derived from tobacco, a few drops 
being sufficient to kill an animal. Its effects upon 
young people are especially serious, producing 
nausea, vomiting, vertigo, weakness, heartburn, con¬ 
vulsions, and unsteady nerves. Its use, at first, pro¬ 
duces a mild stupor, which is followed by restlessness 
and muscular weakness. Without doubt, it deadens 


348 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

the sensibilities and impairs the brain power. While 
it affects in a no less degree the senses of hearing, 
seeing, smelling, and tasting, its filthy, disgusting 
appearances and effects, when chewed, are very 
offensive to the sight. Smoke, especially from an 
old pipe, will cause headache and even fainting, and 
general derangement of the stomach. 

Its effects upon the morals are daily apparent when 
persons insist upon smoking in crowded railroad 
waiting-rooms, cars, and street cars, totally oblivious 
either to the presence, comfort, or health of ladies. 
Many legislatures are now framing laws to prohibit 
expectorating in public places and conveyances, 
which is chiefly due to tobacco users. 

The Use of Cigarettes seems to be more prevalent 
among the young, and there are, aside from this fact, 
two dangers in this habit: The smoke is inhaled and 
then exhaled through the nostrils, burning, searing, 
discoloring, poisoning the delicate membranes of the 
lungs. In short, it is turning this most delicate 
organ into a smoke-house of the vilest sort. Again, 
the cigarettes generally are adulterated with opium — 
a drug of most dangerous and poisonous character. 
Now, the physical effects of cigarette-smoking are 
seen in the pale, sallow complexion, yellow fingers, 
and trembling limbs, while its effects eventually are 


HYGIENE. 


349 


noticed in loss of will-power, sense of morality, 
power of application, with a general unfitness for 
mental application and terminating in forms of in¬ 
sanity and suicide* There is an organization of 
ladies, widely known in this country, whose efforts in 
putting down the use of tobacco and alcohol ought 
to be seconded most heartily by every well-meaning 
citizen. 

But the cases of “ tobacco poisoning ” by means of 
nicotine are very rare. The mischief done by smok¬ 
ing cigarettes or by the excessive use of tobacco is of 
slow growth and effect, but nevertheless sure. To 
one not used to smoking, the effects of a small dose 
of tobacco are well known. The effects from an 
excessive use of it are: A tendency to lower the 
general health; to decrease the digestive capacity; 
and to weaken or irritate the nerves and brain. 
While the temperate use of tobacco apparently 
works no harm in adults, this does not argue that 
it is beneficial to them; and its use by the young 
should at all times be condemned, because to them 
even a mild use of it is hurtful to the highest degree. 

4. NARCOTICS. 

Narcotics Are Drugs which induce sleep or 
insensibility. The principal narcotics in use are (1) 


350 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


opium and morphium , or morphia , (2) chloroform , 
(3) sulphuric ether , (4) chloral , (5) cocoaine , (6) 
bromide of potassium, (7) belladonna , (8) digitalis , 
(9) alcohol. 

In smaller doses these substances cause sleep; in 
larger doses, insensibility, which may terminate 
fatally. 

(1) Opium.* — Laudanum and morphium, pare¬ 
goric and Dover’s powders — these substances are the 
most effective and reliable narcotics. Laudanum is 
a preparation of opium, which is the thickened juice 
of the poppy-plant found in Asia. Morphium or 
morphia, is the most valuable part of opium; it is 
the morphium in opium which renders opium effec- 


*The opium-eater loses none of his moral sensibilities or as¬ 
pirations ; he wishes and longs earnestly as ever to realize what 
he believes possibilities, and feels to be exacted by duty; but 
his intellectual apprehensions of what is possible infinitely 
outruns his power, not of execution only, but even the 
power to attempt. He lies under the weight of incubus 
and nightmare; he lies in sight of all that he would 
fain perform, just as a man forcibly confined to his bed by the 
mortal languor of a relaxing disease, w 7 ho is compelled to witness 
injury and outrage offered to some object of his tenderest love; 
he curses the spells which chain him down from motion; he 
would lay down his life if he might but get up and walk; but he 
is powerless as an infant, and cannot even attempt to rise.”— De 
Quincey's Confessions of an Opium Eater. 




HYGIENE. 


351 


tivo as a narcotic. This class of narcotics may 
relieve pain even without causing sleep. Lettuce and 
dandelions have similar but far milder effect in 
causing sleep. Opium is administered especially in 
typhus fever and other disorders, when delirium and 
loss of sleep may become dangerous to life. But 
opium also acts as a drawback, as it tends to disturb 
the stomach. And the habit of “ eating ” opium is a 
terrible practice, particularly to the young, affecting 
the stomach, muscles, and nerves. Yet the great 
Boerhaave called opium “ the finger of God/’ 

(2) Chloroform. — This powerful anaesthetic, a 
product of alcohol, was first introduced by Simpson, 
of Boston, 1847. It is a very convenient remedy to 
annul pain, but a very dangerous one, as some per¬ 
sons are particularly likely to be affected by it in the 
heart. It is especially useful in surgical operations. 

(3) Sulphuric Ether .— This is a colorless liquid, 
the vapors of which, when inhaled, blunt the senses, 
especially the sense of pain, so that even severe pains 
are no longer felt, and short operations may be per¬ 
formed during the time inhalation goes on. When 
the inhaling process ceases, sensibility returns almost 
immediately. It is a much safer narcotic than opium 
or chloroform. 

(4) Chloral .— This substance, also derived from 


352 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

alcohol, is most likely to affect the heart, and is a 
valuable remedy for simple sleeplessness. Yet, its 
continued use may become a dangerous habit, and a 
physician should be consulted in its use. 

(5) Cocoaine .— This is an alkaloid obtained from 
the leaves of coca . This drug has but recently 
been introduced into medicine, and has become very 
prominent on account of its being the strongest 
local anaesthetic known; that is, it deadens the 
sensibility of a single organ without affecting the 
others; for example, if applied to the eye it produces 
complete insensibility of the cornea and conjunctiva, 
which permits operations to be performed on this 
delicate organ without the aid of chloroform or ether. 

Another remarkable property of this substance is 
its anaesthetic effect upon the mucous membrane. 
Like all narcotics it should be taken or admin¬ 
istered with great caution; and the effects of its 
abuse are terrible. 

(6) Bromide of Potassium is usually adminis¬ 
tered to restore brain and nerves from the fatigue 
produced by overwork. It, too, however, has, like 
all narcotics, its disagreeable features, one of which 
is its weakening influence on the muscles. 

(7) Belladonna , and (8), Digitalis .— Both are 
remedies for strengthening the heart and the arteries, 


HYGIENE. 


353 


and preventing too free a flow of blood to the brain. 
They should be used with caution and under the 
direction of medical advice. 

(9) Hasheesh , the juice of Indian hemp, is said 
to be used by millions of the inhabitants of Asia. 
It is not much known in the western countries. In 
the East the excitement caused by its use takes the 
form of furious madness, leading its victim to 
commit acts of violence and murder. Hence the 
term “ hasheeshers ” in our language has come to 
be synonymous with assassins — Hutchison . 

Of all the ills that suffering man endures, 

The largest fraction liberal Nature cures, 

Of those remaining, ’tis the smallest part 
Yields to the efforts of judicious Art; 

But simple kindness, kneeling by the bed 
To shift the pillow for the sick man’s head. 

Give the fresh draught to cool the lips that burn, 

Fan the hot brow, the weary frame to turn,— 

Kindness, untutored by our grave M. D.’s, 

But nature’s graduate, when she schools to please, 

Wins back more sufferers with her voice and smile 
Than all the trumpery in the druggist’s pile. 

_Dr. Holmes, “ The Morning Visit .” 


23 


354 ANATOMY, PHYSIOLOGY, AND HYGIENE. 


REVIEW QUESTIONS. 

1. How is it known that intemperance is hereditary? What 
does Dr. Allen say about spirits? 

2. Quote Pope’s favorite stanza. Explain the last line. 

3. Tell what is said about the influence of alcohol upon 
humanity. What does Brand say? 

4. Give the derivation of the word alcohol. When was the 
drug first used? 

5. What was alchemy? What is chemistry? 

6. Who was Brown-Sequard? Dr. Koch? 

7. Who brought alcohol into Europe? How has it spread? 

8. Describe alcohol. How does it produce the sensation of 
cold? 

9. State something of its chemical composition. How is it 
related to the sugars? 

10. Give an experiment showing how the presence of alcohol is 
made evident. 

11. Give several of its uses in the arts. In medicine. In other 
sciences. 

12. State several general effects of alcohol. Describe delirium 
tremens. 

13. Is alcohol a food? What is the testimony of an Arctic 
explorer? 

14. How does it produce thirst? Why does the drinker 
imagine he is warm when he is not? 

15. Explain fully the action of alcohol upon the heart. How 
does it increase the number oMieart-beats? Sum up its effects. 

16. Likewise, give its effects upon the lungs. 




HYGIENE. 


355 


17. Give its effects upon the stomach. How dots alcohol 
first reach the blood? What were the results of Dr. Beaumont’s 
experiments upon St. Martin? State its effects upon the different 
fluids, membranes, etc., in the stomach. Give the effects in order. 

18. In the same manner, state its effects upon the liver. What 
disease of this organ is produced by alcohol? 

19. How does it affect the blood and the blood-vessels? Give 
the effects in detail. 

20. State its effects upon the brain tissue. Upon the action of 
the brain. What brain diseases are produced by it? How does it 
affect the moral sensibilities? Tell what Charles Richet says 
about its effect upon the faculties. 

21. Name several liquors, containing considerable alcohol. 
Which are made from grains? Which from fruits? 

22. Name several kinds of wines. Do home-made wines con¬ 
tain much alcohol? 

23. How should coffee and tea be used? What relation do 
chocolate and cocoa bear to foods? 

24. Give the history of tobacco. Tell the little incident that 
happened to Sir Walter Raleigh. 

25. Give the properties of “the weed.” Where is tobacco 
cultivated? How did the name originate? 

26. What is the active principle in tobacco? From whom 
named? 

27. Give the effects of tobacco. Why are its users so careless 
of the comfort of others? 

28. What is the especial danger in cigarettes? Are they widely 
used? In what respect do their use and composition differ from 
those of tobacco? 

29. What is a narcotic? Name several. What is the different 
results according to the size of doses? 

30. Name the forms of opium. Where is the native home of 
this drug? What are its effects? 


356 


ANATOMY, PHYSIOLOGY, AND HYGIENE 


BLACKBOARD OUTLINE. 

ALCOHOL. - STIMULANTS - NARCOTICS - THEIR 
EFFECTS. 


1. Alcohol. 

History and Properties. 
Manufacture. 

f General. 


Uses — Effects. < 


, Specific. 


f Mind, 

\ Body. 

f On the Heart, 

On the Lungs, 

On the Stomach, 
i On the Liver, 
i On the Blood and 
Blood-vessels, 
On the Brain and 
Nervous System. 


2 . Wine, Kum, Brandy, Arrack, ami Oilier Spiritnons Liquors. 

Their Properties and Uses. 

3 . Tobacco. 

History and Properties. 

Production. 

Uses and Effects. 


4. Narcotics. 

Opium, 

Chloroform, 

Sulphuric Ether, 
Kinds, Properties, Chloral, 

Uses and Effects.Cocaine, 

Bromide of Potassium, 
Belladonna, 

Digitalis, 

(.Hasheesh. 






X. 


EMERGENCIES. 


The TEadinEss is all ,— Hamlst, 

( 357 ) 











# 




X. Emergencies. 


1. DROWNING. 

Marshall Hall's “Ready Method” of treatment 
in asphyxia from drowning, chloroform, coal-gas, 
etc. 

1st. Treat the patient instantly on the spot , in the 
open air , freely exposing the face, neck, and chest to 
the breeze, except in severe weather. 

2d. In order to dear the throat , place the patient 
gently on the face, with one wrist under the fore¬ 
head, that all fluid, and the tongue itself, may fall 
forward and leave the entrance into the windpipe 
Iree. 

3d. To excite respiration , turn the patient slightly 
on his side, and apply some irritating or stimulating 
agent to the nostrils, as veratrine , dilute ammonia , 
etc. 

4th. Make the face warm by brisk friction; then 
dash cold water upon it. 

5th. If not successful, lose no time; but, to imi- 

(359) 


360 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

tate respiration , place the patient on his face, and 
turn the body gently, but completely on the side , and 
a little beyond; then again on the face, and so on, 
alternately. Repeat these movements deliberately 
and perseveringly, fifteen times only in a minute. 
(When the patient lies on the thorax, this cavity is 
compressed by the weight of the body, and expiration 
takes place. When he is turned on the side, this 
pressure is removed, and inspiration occurs.) 

6th. When the prone position is resumed, make a 
uniform and efficient pressure along the spine , remov¬ 
ing the pressure immediately, before rotation on the 
side. (The pressure augments the expiration, the 
rotation commences inspiration.) Continue these 
measures. 

7th. Rub the limbs upward with firm pressure and 
with energy. (The object being to aid the return of 
venous blood to the heart.) 

8th. Substitute for the patient’s wet clothing, if 
possible, such other covering as can be instantly pro¬ 
cured, each bystander supplying a coat or cloak, etc. 
Meantime, and from time to time, to excite inspira¬ 
tion, let the surface of the body be slapped briskly 
with the hand. 

9th. Rub the body briskly until it is dry and 


EMERGENCIES. 


361 


warm, then dash cold water upon it, and repeat the 
rubbing. 

Avoid the immediate removal of the patient, as it 
involves a dangerous loss of time; also, the use of 
bellows, or any forcing instrument; also, the warm 
bath , and all rough treatment . 

2. CUTS. 

Hemorrhage from Divided Arteries should be 
Arrested, otherwise the heart soon ceases its action, 
and the person faints. If a large artery is 
wounded, every beat of the pulse throws out the 
blood in jerks. Until surgical help can be sum¬ 
moned, the flow of the blood may be stopped either 
by compressing the vessel between the wound and 
the heart, or by compressing the end of the artery 
next the heart in the wound. 

After compression as described and illustrated, 
take a square piece of cloth, or handkerchief, 
twist it cornerwise, and tie a hard knot in the 
middle. Place the knot over the artery between 
the wound and the heart, carry the ends around 
the limb and tie loosely. Place a stick under the 
handkerchief near the last tie, and twist till the 
fingers can be removed from the compression with¬ 
out a return of the bleeding. When an artery in a 


362 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


limb be cut, elevate the limb as far as possible, till 
the bleeding ceases.” 



FIG. 69. FIG. 70. 


Fig. 69. The method of applying the knotted handkerchief, 
to compress a divided artery. A, B , Track of the brachial 
artery. 

Fig. 70. A, C, The track of the femoral artery; the compress 
applied near the groin. 


3. BURNS. 

If the clothes catch fire, wrap the person quickly 
in a coat, mat, shawl, carpet, or any other woolen 
article, to extinguish the flame, and lay him down at 
once. Pour on plenty of water to cool the burning 
clothing. The party should then be carried to a 
warm room and laid on a table or carpeted floor. 
Remove the clothing carefully with scissors or knife. 


EMERGENCIES. 


363 


Do whatever can be clone to keep the air from the 
burns. Soft cloths wet with sweet oil, applied to the 
parts, is a good accessory. 


4. CONVULSIONS. 

These may be trivial or grave. If it is a young 
woman, the attack is probably hysterical and, as a 
rule, not dangerous, and a sprinkle of cold water will 
bring relief. If the patient struggles with regularity 
of movement, and there is bloody froth on the lips, 
it is a case of epilepsy, and requires a physician’s 
attendance. Meanwhile protect the head from injury 
by putting a pillow or some soft article beneath it; a 
cork introduced between the teeth will prevent the 
biting of the tongue. Prevent the patient from fall¬ 
ing or injuring himself, but do not attempt to forcibly 
hold him quiet. 

In children, apply cloths dipped in water to the 
head; disturb the child as little as possible; do not 
use a warm bath until directed by the doctor. 

































































XI 


APPENDIX. 


When all has been said there is still mare tn be added, 

— Morgan, 


( 365 ) 



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IX. Appendix. 


SKELETON — Classification of Bones. 

Classes of Bones as to Shape ■ 

1. Long Cylindrical: 

Femur, 

Humerus, 

&c. 

2. Short Cylindrical: 

Phalanges, 

Carpals, 

&c. 

3. Flat: 

Scapula, 

Sternum, 

&c. 

4. Irregular: 

Sphenoid, 

Sacrum, 

&c. 


CIRCULATION. 

Portal Circulation.— There is apart of the systemic circulation 
called by some the portal circulation. It is that part which con¬ 
veys the blood into and from the liver, called by this name from 
the Latin word, porta, a gate, because the blood-vessel enters the 
liver by a kind of gateway, The veins from the stomach, spleen, 

( 367 ) 


368 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


pancreas, and intestines unite in forming one large trunk about 
three inches long, called the portal vein. This enters the liver 
where its subdivisions are well distributed. These subdivisions 
then come together into one vessel known as the hepatic vein. 

The food which the capillaries absorb directly through the 
walls of the stomach and intestines, is carried into the liver. In 
the liver a change goes on but no one positively knows what it is. 
Sugar seems to be changed to a kind of starch and is stored in 
the liver for future use. When needed, is changed back to sugar 
and taken up by the circulation. It will be remembered that 
there are two ways by which the nutriment of the food 
reaches the blood — one through the walls of the alimentary canal 
into the lacteals thence into the thoracic duct which empties into 
the vena cava, the other through the walls of the alimentary canal 
directly into the capillaries into the blood. The latter is through 
the portal circulation. It has been thought that the nourishment 
from sugars and starches, etc., reaches its destination by way of 
the portal circulation, while that from fats passes through the 
lacteals. 


DISSECTION. 

Heart.—No amount of description will give a full, correct 
understanding of the heart. This is true also of many other 
organs of the body. Get the actual thing and cut it up. Secure 
the heart of some animal, as the ox, sheep, hog, or any other 
of the mammals. Wash clean, then fill with water to observe 
its shape. Now empty and cut as follows: Cut off the auricles 
just above their lower margins. Observe the appearance of 
the valves from above. Then cut vertically through from right 
to left. Wash again so as to get the best possible view of the 
structure. Notice valves, walls, cavities, etc. Cut out through 
the arteries to see their structure and valves. 


APPENDIX. 


369 


Lungs. — Get the lungs of a sheep, or of some other animal; 
the sheep is best. See that lungs, trachea, and larynx are all 
intact. Wash thoroughly. They must be fresh from the animal 
and not allowed to dry. When well cleaned place the mouth at 
the top of the larynx and blow with force so as to fill the lungs 
with air. Now compress the lungs. Repeat this experiment — 
observing the action of the lungs. To examine the structure cut 
transversely through larynx from front to back, and through 
trachea from right to left. In the lung itself split the bronchial 
tubes, running the knife out through the lung substance. Wash 
at each cutting. 

These examples are suggestions. The energetic student and 
the wide awake teacher will find and use other parts. 


POISONING, 

When a person is discovered to have swallowed poison, unless 
vomitiug has already occurred, empty the stomach by an emetic 
that can be most readily and quickly obtained, and is prompt and 
energetic, but safe in its action; for this purpose, there is, 
perhaps, nothing better than a large teaspoonful of ground 
mustard in a tumblerful of warm water. If the mustard is not at 
hand give 2 or 3 teaspoonfuls of powdered alum in syrup or 
molasses, and give freely of warm water to drink; or give 20 gr. 
of sulphate of zinc (white vitriol), or of ipecac, in a large cup of 
warm water and tickle the throat with the finger, or with the 
feather end of a quill; copious draughts of warm water or 
mucilaginous fluid should be given to keep vomiting up until the 
poisonous substances have been thoroughly evacuated, and then 
suitable antidotes should be given. If vomiting cannot be pro¬ 
duced, the stomach pump should be used. 


24 















































































































. 




























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.• - • • ' • : ^ 

1 ' X • * 8 • 

































































































GLOSSARY. 


CONTAINING THE ANATOMICAL AND PHYSIOLOGICAL MEANING* OF 

CERTAIN TERMS. 

Ab-do'men. The largest cavity of the body; below the dia¬ 
phragm and above the pelvis, containing the stomach, 
intestines, liver, spleen, etc. 

Ac'id. A substance generally sour to the taste, which changes 
vegetable blue colors to red, and combines with bases to 
form salts. 

Adipose'. Fat, or fatty. 

Albu'men. A substance like the white of an egg, coagulating 
by heat. 

Alcohol. A result of the decomposition of sugar. 

AVi-ment. Nourishment; food. 

Al-i-ment’ary Ca-nal. A tube passing through the body, begin¬ 
ning with the mouth, piercing the diaphragm, and termi¬ 
nating with the rectum, by which nourishment is taken 
into the body, digested, and indigestibles execreted. 

Aor'ta. The great artery arising from the upper and the back 
part of the left ventricle of the heart; the common trunk 
of the arteries of the body. 

Apparatus (Physiol.). A system of organs concerned in some 
special function of the animal body. 

Arrack. Product of the distillation of rice or palm-juice. 

Ar'tery. Any branch of the aorta conveying blood in the direc¬ 
tion from the heart to all parts of the body. 

As-sim-i-la'tion. The conversion of food into the substance of 
organized beings. 


( 371 ) 


372 ANATOMY, PHYSIOLOGY, AND HYGIENE. 

Au'ricle. The external ear. Hence one of the two venous 
chambers of the heart, resembling the external ear. 

Beer. A fermented liquid made from any malted grain, with 
the addition of hops and other substances. 

Bi'ceps. Two-headed. A muscle attached to the shoulder- 
bone, connecting it with one of the bones of the fore¬ 
arm. 

Bicus'pid. A molar tooth having two points. 

Brandy. A result of the distillation of strong wines. 

Bronch'us. The windpipe, or trachea. The bronchi , or bronchia , 
now mean the two tubes which arise from the bifurcation 
of the trachea, and carry air into the lungs. 

Cognac. A result of the distillation of strong wines. 

Cam r era-obscu f ra. An instrument used in a darkened room to 
throw images of external objects upon a surface. 

Ca-nine \ Applied to teeth, it means the pointed tooth next 
to the incisor. It is often quite long. 

Cap f -il-la-ries. A net-work of minute blood-vessels, connecting 
the termination of the arteries with the termination of the 
veins. 

Car'di-ac. From the Greek kardia , the heart. 

Carniv’orous. Flesh-eating. Carnivore , a carnivorous animal. 

Car'ti-lage % or gristle. A dense, firm substance of less hard 
tissue than bones. 

Cell. A small, distinct, spheroidal mass of protoplasm or living 
material. 

Cer-e-beVlum. The little brain, beneath the cerebrum. 

Cer'e-brum. The brain proper, occupying the entire upper 
portion of the skull. 

Cho'roid. A coat containing a great many blood-vessels, lining 
the interior surface of the sclerotic coat of the eye. 

Chyle. A milky fluid formed in the process of digestion by the 
action of the pancreatic juice and the bile on the chyme in 
the duodenum. 


GLOSSARY. 


373 


Chyme. A pulp formed by the action of the stomach on the 
food. 

CiVi-ary Processes. The minute radiating ridges formed around 
the iris by the anterior portion of the choroid. 

Clav'i-cle. The collar bone. 

Coch'lea. A cavity of the ear resembling a spiral shell. 

Colie'rence . The act or state of cohering. 

Co'lon. That portion of the large intestine extending from the 
caecum to the rectum. 

Connective tissue. The connective medium by which the dif¬ 
ferent parts of the body are held together. It passes from 
the dermis between all the other organs, ensheathing the 
muscles, coating the bones and cartilages, and ultimately 
entering into the mucous membranes. 

Contractile. Having the power of contraction. 

Corpus'cle. Minute body or particle of matter. 

CutUcle. The superficial layer of the skin. The same as epi¬ 
dermis. 

Cutis. The deeper portion of the skin. The same as dermis. 

Degluti'tion. The act, or power, of swallowing food. 

Delirium Tremens. Usually the result of continuous intoxica¬ 
tion. 

Dentine. The principal constituent of a tooth. 

Derivation. Transmission of anything from its source. 

Dermis. The same as cutis. (See this.) 

Diaphragm. The muscular partition separating the chest from 
the abdomen, and assisting respiration. 

Diastole. A dilatation of the heart and arteries; opposed to 
systole. 

Digestibility. The quality of being digestible. 

Dilatation. Expansion. 

Duodenum. The first of the small intestines; is about as long 
as the breadth of twelve fingers. 

Enam'el. The hard exterior surface of the teeth. 


374 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


Epidermis. The same as cuticle. (See this.) 

Epiglot'tis. A cover on the aperture of the windpipe. 

Eu-sta'chi-an Tube. A tube extending from the inner side of 
the tympanum, opening at the back of the nostrils. 

Fetor. A strong, offensive smell. 

Fi'brine or fibrin. A white, tough, fibrous substance, obtained 
from coagulated blood. 

Function. Performance, office work, action. 

Gan'gli-on, pi. ganglia. A mass of nerve-cells, forming a center 
from which nervous fibres radiate. 

Gas’trie. Belonging to the stomach. 

GloVtis. Aperture at the top of the larynx. 

Hem'or-rhage. Loss of blood; bleeding. 

Herbiv’orous. Feeding of plants. Herbivore , herb-eating animal. 

Hy’gi-ene. The knowledge of the preservation of health. 

Il'eo-jeju'num. The part of the small intestine immediately 
succeeding the duodenum. 

Incis'ors. The four front teeth of both jaws. 

Innervaton. The function of the nervous system. 

Inorgan’ic. Destitute of organs or animation. 

In-sal-i-va'-tion. The mixing of food with saliva. 

Tris. A membrane with an aperture in the center, stretched 
vertically across the eye, and separating the anterior from 
the posterior chamber. It gives the eye its color. 

Lab'y-rinth. The internal ear. 

Lac'te-al. A lymphatic vessel of the intestinal canal. (See 
Lymphatic.) 

Lar'ynx. Cavity at the top of the trachea, the organ of voice. 

Lever. A stiff bar or rod, which turns on, or is supported in, a 
fixed point. 

Lig'a-ment. A strong fibrous material, uniting bones or other 
solid parts together. 

Liquors. Highly flavored liquids containing large quantities of 
alcohol and sugar. 


GLOSSARY. 


375 


Lymphat'ic. Vessel conveying a colorless, watery fluid, called 
lymph , to the thoracic duct. 

Mas-ti-ca'tion. The act of chewing. 

Me-dal'la Ob-lon-ga'ta. “ The oblong marrow.” Portion of the 
nervous cord within the skull nearest to the spinal cord. 

Mem'brane. A thin layer of tissue, serving to separate, cover or 
envelop other organs. 

Mo’lar. A grinding tooth. 

Mo'tor. Giving motion. 

Mu'cous Mem'brane, or Mucous Coat. The continuation of the 
skin, in apertures and interior cavities: that is, the lining of 
the internal cavities. 

Mu'cus. A more or less tenacious fluid. 

Narcotics. Remedies inducing sleep or insensibility. 

Nutri'tion. The conversion of food into nutriment. Sometimes 
used to comprise digestion, absorption, respiration, circula¬ 
tion and assimilation. 

CE-soph'a-gus. The tube which extends from the interior portion 
of the pharynx to the stomach; the gullet. 

Organ'ic. Having organs, animation; or, pertaining to organs. 
Hence, organism = an organic being. 

Ossification. The formation of bone. 

Pal'ate. The roof of the mouth. 

Pancreas , or “ sweet-bread .” A gland of the abdomen, under 
and behind the stomach, at the right of the spleen. 

Pel'vis. Two separate bones to which the legs are attached, and 
which bound the abdomen below. 

Phys-i-ol'o-gy. The science of the functions of animals and 
vegetables. Human physiology is the science which treats 
of the functions of the human body and the manner in which 
they are brought about. 

Proc'ess. Eminence of a bone; a portion prolonged beyond 
others with which it is connected. 

Pul'mo-na-ry . Pertaining to or affecting the lungs. 


376 


ANATOMY, PHYSIOLOGY, AND HYGIENE. 


Py-lo'rus. The lower or right orifice of the stomach. 

Ret'i-na. A very delicate membrane, lining the hinder two- 
thirds of the eye-ball. It is the continuation of the optic 
nerve. 

Rhythm. A measure of anything according to the number of 
regularly occurring impulses. 

Rigor Mortis. Stiffness of the entire body after death. 

Rum. Product of distillation of fermented sugar cane. 

Sa'crum. The tr iangular bone forming the posterior part of the 
pelvis, and terminating the vertebral column. It is a union 
of the 25th, 26th, 27th, 28th and 29th vertebrae into one great 
bone. 

Sa-li'va. A thin watery liquid of the mouth, having the property 
of converting starch into sugar. 

Sapidity. The quality of bodies that gives them taste. 

Scle-rot'ic. The white of the eye. A tough, firm spheroidal case, 
the greater part of which is white and opaque. 

Se-cre'tion. The separation of substances from the blood of 
animals, or from the juice of plants. 

Sensibility. The power which any tissue of the body has of 
causing changes inherent or excited on it to be perceived 
and recognized by the mind. 

Se'rum. Watery part of animal fluids, as of blood or milk. 

Skel'e-ton. The solid framework of the body of an animal. 

Stimulant. Means of increasing the vitality of some organ or 
of the human system. 

Sympathetic. A long double series of ganglia connected to¬ 
gether by nervous cords. 

Sys'to-le. The contraction of the heart — opposed to diastole. 

Tac'tile. Percepticle to, or susceptible of, touch. 

Tem'perature. The amount of heat which a body may communi¬ 
cate to other bodies. 

Ten'don. A white cord attached at one end to a bone aud at 
the other end to a muscle; the same as sinew. 


GLOSSARY. 


377 


Tho'rax. The chest; the part of the body between the neck 
and the abdomen. 

Thoracic. Pertaining to the thorax. 

Tis'sue. A membranous organization of parts. 

Tra'chea, or Trach'ea. A tube strengthened by cartilaginous 
rings extending from the larynx downward along the front 
part of the thorax, and passing into the thorax where 
it divides into two branches, a right and a left, called 
the bronchi. 

Tym'pa-num, or Drum. Cavity of the middle ear, separated 
from the external ear by the tympanic membrane. 

Vein. A vessel to convey venous blood to the heart. 

Ven'tricle. Generally applied to the two cavities of the heart 
which communicate with the auricles. Applied also to other 
cavities in the body. 

Ver'te-bra , pi. Vertebrce. One of the bones composing the ver¬ 
tebral column. It consists of a main part, called the body 
of the vertebra; and of seven projections called processes. 

ViVli. Soft projections or processes covering certain mem¬ 
branes. 

ViVre-ous Humor. The transparent mass which fills the eye 
behind the crystalline lens. 

Wine. Fermented juice of the grape. 

Whisky. Product of distilling wheat, rye or corn. 









. 







INDEX 



PAGE. 

Abdomen. 


Absorption, poison . 

.133 

food. 


Achilles, Tendon of 


Age. 


Air.145, 

146, 166-170, 177 

Air-eells . 


Albumen. 


Albinos. 


Ale. 


Alcohol. 


properties of .... 

.331 

manufacture of.. 

. 332 

uses of. 


effects of . 

.333-345 

Animals. 

. 3, 4, 6, 7, 9, 321 

Animal functions ... 


Anatomy . 


Apoplexy. 

. 344 

Apparatus . 


Appendix. 


Aqueous humor. 

.298, 302 

Arbor vitae. 

. 262 

Arm. 

. 34 

Arrack . 

. 346 

Arteries. 

. 112, 113 

structures of. 

.114, 115 

Assimilation . 

.215-222 

Asphyxia. 


Attention . 


Auditory canal. 


nerve.. 


Auricles . 


Bathing, manner of.. 

. 89 

time of. 

. 90 

the eye. 

.317 

Bed. . 


Beer. 

.346 

Belladonna . 

. 352 

Bile. 

. 213 


PAGE. 

Biology. 9 

Blackboard Outline — 

Introduction. 13 

Osseous system. 46 

Muscular system. 79 

Skin, hair, and nails. 98 

Circulation.142 

Respiration.182 

Digestion.250 

Nervous system. 327 

Stimulants. 356 

Blood, composition of-.103-105 

specific gravity of... 106 

quantity of.106 

uses of .106,108, 133 

circulation of. 112, 119-124 

purification of.161,169, 340 

Blushing. 134 

Body.5, 189 

Bones, composition of. 18 

structure of. 19 

growth of. 19 

repair of. 21 

functions of... 41 

fractures of. 43, 44 

classes of. 367 

Bones of the ear. 309 

Boneblack. 17 

Botany. 2 

Boxing the ear. 318 

Brain.24, 256, 315, 349 

structure of.259, 261 

membranes of.260 

functions of . 269 

Brandy. 346 

Bronchi. 40, 153, 154 

Buildings. 179 

Burns.362 

Canal, Haversian . 19 

alimentary.25, 196 


( 379 ^ 



















































































380 


ANATOMY, PHYSIOLOGY, AND HYGIENE 


Capillaries . 

structure of. 
Casein« . 

PAGE. 

.112, 113, 124, 126, 154 

. 118, 119 

. 229 

Cardiac orifice.. 

. 195 

Dfltnrrh . 

. 134, 135 

Cartilage . 

. 19, 20, 33, 38 

q, a i , . 

. 119 

Polls . 

. 21 

Center of gravity. 60 

Cerebrum . 

.260 

Cerebellum. 

.262 

functions of 

.271 

Chest. 

.21,24 

Chilblains. 

. 95 

Chyme. 

.209, 211 

Chyle.. 

.213, 214 

Choroid . 

. 297, 302 

Chocolate . 

. 346 

Chloroform . 


Chloral . 

. 350 

Circulation . 

. 103 

important facts of. . 137-139 

Cilia . 

. 153 

Ciliary processes . 297 

Cider . 

. 346 

Cigarettes . 

. 348, 349 

Clay . 


Clothing . 


Clot . 


Climate . 


Coherence ... . 


Cohesion . 

. 6 

Compound .... 

n 

Corns . 


Contractility. .. 


Cosmetics . 


Corpuscles . 


Congestion . 

. 133 

Cold. 

.135 

Conduction .... 


Cords, vocal .. 

.155, 158, 164 

Coughing. 


Cooking. 

. 239 

Cornea. 


Conjunctiva.... 


Color-blindness 


Cochlea. 


Cognac. 


Coffee. 



PA(t K. 

Cocoa .346 

Cocoalne.352 

Convulsions.363 

Crystal.5, 6 

Crying . 165 

Cranium. 259 

Crystalline lens .298, 302, 307 

Cuticle. 81 

Cuts. 361 

Dandruff.82, 94 

Decay. 6 

Dermis (cutis vera)..81,83 

Deglutition.207, 208 

Decussation.272, 275 

Deafness.319 

Discs. 54 

Diastole. 120 

Diaphragm ..156,161 

Digestion. 205-222, 241,242 

Diet. 238 

Dyspepsia .243 

Digitalis. 352 

Dissection.368 

Draught. 173,319 

Drowning. 359 

Dust.317 

Ear-wax.309,3i.8 

Eczema . 95 

Elements. 7 

Emergencies. 357 

Endosmos . 168 

Energy.. 4 

Epiglottis.40,156 

Epidermis (cuticle) 81, 82,285, 294,313 

Epilepsy. 314 

Eskimos. 233 

Ether.•. 351 

Eustachian tube.310, 312, 319 

Exercise, reasons for.70, 71, 72 

effects of. J 32 

kinds of . 71, 72 

Excretion, skin. 84 

Expiration . 162 

Exsomose . 168 

Eye . 294, 316 

Eyeball. 294, 303 

coats of.204 

humors of. 204 






































































































INDEX 


381 



PAGE. 

Eyebrows . 


Eyelids . 


Fat. 

52, 53 , 2^9 

Fibre. 


Fibrine . 

103, 105, 228 

Form . 


Foot. 


Force . 


Foot-pound. 


Food. 189, 

190, 223-239 

sources of. 


classes of. 

225, 227, 237 

quantity and quality of.232 

how and when. 

.... 238,240 

Froenum linguae. 

. 193 

Functions. 


Gas, CO 2 . 


in blood. 


in air. 


oxygen. 


hydrogen . 

. 226 

nitrogen. 


odors. 

.293 

Gaping. 

. 166 

Gastric juice. 

. 195, 206, 338 

Gall. 


Ganglia, sympathetic.... 

.256 

Germinate. 

. 4 

Glottis. 

.39, 155 

Glands, oil. 

. S3 

sweat. 

. 83 

lymphatic.. 


salivary. .. 


lachrymal . 

.299 

Glue. 


Glossary . 

.371 

Gum. 


Hair.. 

. 81,85 

functions of. 

. 88 

Hand . 

. 34 

Habit. 

.314 

Hasheesh.. 

.353 

Head . 

.20-23 

parts of. 

... 23 

Hemorrhage. 

. 361 


PAGE. 

Heart.62, 110, 335, 368 

divisions of .ill, 112 

functions of. 113 , 114 

action of.120-127 

Heat.-.147-150 

Health. 232, 233 

Hemiplegia .276 

Hearing. 308 , 318 

Hiccough. 166 

Hunger. 224 

Hydrogen . 7 

Hygiene . 9 

Ideas. 325 

Introduction. 1 

Inorganic matter.I, 7, 8 

Inflammation . 134 

Inspiration.162 

Intestines.196, 199, 213 

Insalivation. 207 

Intestinal juice. 214 

Insanity. 231 

Irritability. 73 

Iron.231 

Iris. 297, 302 

Joints. 20, 35, 36, 57 

important facts. 37 

classes of... 37 

Kingdoms. .. 4 

Kidneys. 204 

Knee...,. 33 

Larynx.,.39, 155-160 

Laughter . 165 

Lacteals. 202, 220, 221 

Lachrymal Glands, Ducts, etc.... 301 

Labyrinth. 310 

Leaping. 61 

Levers . 56 

Leg. 60 

Life . 4 

Lime.18, 231 

Limbs.20-33 

Ligaments. 31, 36 

Liver.199, 200, 339 

Light.303, 316 

Liquor.346 

Lungs.151, 152, 176, 337, 369 































































































382 


ANATOMY, PHYSIOLOGY, AND HYGIENE 


PAGE. 

Lymphatic circulation. 127 

Lymphatics, structure of.127-129 

absorption by. 222 

Lymph. 130 

Matter. 3-5 

growth of.5, 6, 7 

organic.—4, 5 

inorganic.4, 5 

composition of.5-7 

animal. 17 

mineral . 4,17 

vegetable. 4 

Marrow. 10 

Mastication. 206 

Medulla Oblongata. 262 

functions of.272 

Mental Derangement.270 

Mind. .132, 320, 322 

Moaning. 166 

Mouth.191 

Morals . 343 

Mucus. 292 

Muscles.8, 32 

experiments. 51 

properties of. 52 

structure of. 53 

number of. 53 

of head and trunk . 62 

relaxation of. 63 

kinds of.66, 67, 68 

arrangement of.... 68 

functions of.68, 69 

development and exercise... 70 

important facts. 74 

Myopia. 306 

Nails.81, 85, 86 

functions of. 86 

important facts. 92 

ingrowing. 94 

Narcotics.329, 349 

Nervous system, objects of...251-255 

structure of.256-258 

divisions of.256 

Nerves, spinal...256, 265 

cerebrospinal . 263 

cranial. 264 

sensory . 273, 278 


PAGE 

Nerves — Continued. 

motory.274 , 278 

functions of.277, 288, 313 

roots of.270 

Nicotine. 347 

Occupation. 235 

Oesophagus .194, 208 

Optic nerve.294, 303 

Opium.350 

Organic matter.4, 7,8 

Organs. 4 

of circulation . 108 

of respiration. 150 

of voice .158 

of digestion. 191 

of sense . . .288 

Orbits. 299 

Ossification..18,16 

centers of. 20 

Over-exertion . ... v . 136 

Oxygen.7, 225 

Ozone . 167 

Papillae.83, 288 

Pancreas.200 

Pancreatic juice. 214 

Paralysis. 276 

Pelvis.21, 24, 29, 32 

Perception.324 

Physiology. 9 

human. 9 

comparative. 9 

knowledge of. 10 

Phosphorus. 17 

Pharynx. 194 

Perina. 309 

Plants. . 3 

Pleura. 156 

Pores. 83, 91 

Porter. 346 

Potassium, bromide. 352 

Portal circulation.367 

Poisoning. 369 

Presbyopia. 306 

Pulmonary arteries... 115 

capillaries. 160 

Pulse.123,124 

frequency of. 127 
































































































INDEX. 383 


PAGE. 

Pupil of the eye. 297 

Pyloric orifice.195 

Questions on Introduction. 11 

Osseous system . 45 

Muscular system. 77 

Skin, hair, and nails. 96 

Circulatory system. 140 

Respiratory system . 181 

Digestive system .247 

Nervous system. 280 

Stimulants, etc. 354 

Radiation. 148 

Reaction . 90 

Rest.63, 74 

Reflex action. 273 

Retina. 297, 302-305 

Rhythm.163 

Ribs. 31 

Rickets. 42 

Rigidity, post-mortem. 52 

Rum...346 

Salt.8, 231 

Sartorius muscle. 68 

Sacrum. 32 

Science. 3 

Scrofula.134 

Sense, muscular. 74 

touch.284-286 

taste.287-290 

smell.290-292 

sight.299 

hearing. 308 

Sensibility. 52 

Serum.103-105 

Sex.235 

Semi-circular canals.310 

Sensation . 324 

Shoulder. 33 

Sighing. 165 

Sight..294, 316 

Skeleton, parts and cavities-- 20 

functions of . 42 

Skull.. 21 

Skin.81, 175 

structure of. 81 

functions of. 87 

i 


Skin — Continued. 

PAGE. 

care of . 

. 88 

disorders. 


Skin-grafting . 

... . 92 

Smell. 

.290, 315 

Sneezing. 


Snuff. 


Snoring. 


Sobbing. 


Spinal cord . 


structure of. 


functions of. 

..273 

fibres of. 

. 275 

Spinal column. 

. 24 

Sprain. 

.36,43 

Spleen. 

. . 201 

Standing. 

. 59 

Sternum. . 


Stapedius muscle. 

. 68 

Stomach. 

.194, 338 

motions of. . 

.197, 209 

digestion. 

. 209 

disorders. 

.244 

Starch. 

. 229 

Strabismus. 

.294, 317 

Stimulants ...... . 

....315, 329, 334 

Sutures . 

. 20 

Synovia. 

. 37 

Systole. 


Sympathetic system.. 

.266 

functions of. 

. 276 

Taste. 


Teeth. 


parts of. 

. 25 

number of. 

. 26 

names of. 

. 27 

preservation of... 

. 28 

Tendons.. 

. 56 

attachment of. 

. 65 

uses . 

. 66 

Temperature. 


Tea. 

.346 

Thorax . 

.21, 24, 29 

Thoracic duct. 

.202, 221 

Thought. 

. 325 

Tissue, connective... 

.55, 85 

areolor.. 

. 66 

nerve. 

.266 
































































































384 ANATOMY, PHYSIOLOGY, AND HYGIENE 


PAGE. 

Tonicity. 73 

Tongue.287 

Tobacco, history of.347 

properties of . 347 

effects of. 347 

Trunk..... 20, 24, 28 

Trachea (windpipe).39, 154 

Tympanum.309, 311, 319 

Vertebra.25, 29, 30 

Ventricle.Ill, 112,121,127, 160 

Valves.112,117, 118 

Veins...112, 113 

structure of.116, 1 IS 

Voice.163, 175,177 

Ventilation.171, 174 

Vermiform appendix. 198 


PAGE. 

Villi.220,221 

Vegetative functions.256 

Vitreous humor.298, 302 

Vision.301,316 

Vestibule. 310 

Water.. 7, 180,230 

Walking.60, 72 

Work. 63 

Warts . 93 

Wine.345 

Whisky. 346 

Yawning.166 

Zoology. 9 











































































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